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22 tháng 2 2021

= 1 - \(\frac{1}{2010}\)nha em

#Chúc em học tốt

22 tháng 2 2021

\(N=\frac{1}{1.5}+\frac{1}{5.10}+\frac{1}{10.15}+...+\frac{1}{2005.2010}\)

\(5N=\frac{5}{1.5}+\left(\frac{5}{5.10}+\frac{5}{10.15}+...+\frac{5}{2005.2010}\right)\)

\(5N=1+\left(\frac{1}{5}-\frac{1}{10}+\frac{1}{10}-\frac{1}{15}+...+\frac{1}{2005}-\frac{1}{2010}\right)\)

\(5N=1+\left(\frac{1}{5}-\frac{1}{2010}\right)\)

\(5N=1+\frac{401}{2010}\)

  \(5N=\frac{2411}{2010}\)

\(\Rightarrow N=\frac{2411}{10050}\)

20 tháng 2 2021
ơ thế nếu trong ảnh của bạn thì đoạn AC bằng BC À......
21 tháng 2 2021

\(\frac{S_{APN}}{S_{PNC}}=\frac{AN}{NC}=\frac{1}{3}\)(chung đường cao kẻ từ P)

\(S_{PNC}=100x3=300cm^2\)

\(\frac{S_{BNM}}{S_{NMC}}=\frac{BM}{MC}\)( chung đường cao kẻ từ N). mà 2 tam giác chung đáy NM nên đường cao hạ từ B bằng đường cao hạ từ C

Vậy \(S_{PBN}=S_{PNC}=300cm^2\)(chung đáy PN, đường cao kẻ từ B băng đường cao kẻ từ C)

\(S_{ABN}=S_{PBN}-S_{PAN}=300-100=200cm^2\)\(\frac{S_{ABN}}{S_{ABC}}=\frac{AN}{AC}=\frac{1}{4}\)(chung đường cao kẻ từ B)

\(S_{ABC}=200x4=800cm^2\)

ĐỀ SỐ 1 B.USE OF LANGUAGE: Question II. Find the word which has different sound in the part underlined.(1 point)                                                                                                                                            1. A. wanted                            B....
Đọc tiếp

ĐỀ SỐ 1

 

B.USE OF LANGUAGE:

Question II. Find the word which has different sound in the part underlined.

(1 point)                                                                                                                                           

1. A. wanted                            B. washed                               C. decided                   D. needed

2. A. fun                                     B. sun                                 C. surf                           D. cut

3. A. leisure                            B. eight                                 C. celebrate                   D. penalty

4. A. A. although                    B. laugh                                  C. paragraph               D. enough

Question III. Choose the best answer. ( 2.0 points )

1. The Gong Festivals is held ____________  in the Central Highlands.

A. year                        B. yearly                                 C. annual                                 D. annually

2. YMoan was the greatest pop singer of the  ____________ group in Dak Lak Province.

A. Tay ethnic              B. Thai ethnic                         C. Ede ethnic              D. Muong

3. He was called  “____________ singer of the great woods”.

A. the                          B. a                                          C. an                                        D. the best

4. Teenagers enjoy listening to music and____________  out with friends.

A. hang                                   B. to hang                               C. hanging                              D. hangs

5. Life in a small town is ____________ than that  in a big city.

A. less peaceful                       B. much more peaceful    C. much peaceful             D. peaceful

6. My mother always tells me that I ___________  be home by 9 p.m.

A. has to                      B. have to                    C. have not to                          D. mustn’t

7. When you eating in India, you_______ use the right hand. Never use the left hand.

A. must                                   B. should                     C. shouldn’t                      D. mustn’t

8. ____________ month is the Hoa Ban Festival of the Thai people held in?

A. Which                   B. When                                   C. How many                    D. However

Question IV. Give the correct form of the words in brackets: ( 1.0 point)

1. She   ____________   wear that costume because it’s the family tradition.              (have to)

 

2. In India, you ______ shake hands with women, especially in rural ereas. It’s a taboo.

(must)

3. The wai is the __________   greeting of people in Thailand.                           (tradition)

4. In Australia, you mustn’t ___________   on a person’s accent.                         (comment)

C-READING:

Question V: 1. Read and complete the passage with words in the box. (1.5 point)

          

In addition                     Also                          As I have noted

In my opinion                Besides                                 I think

My favorite leisure activity is listening to music.(1)_____________, listening to music not only helps me relax but also provides me with musical knowledge. I (2)________ like the time that I can lie lazily in bed, put on the small earphone with my iPod and enjoy any favorite songs of many kinds of music: pop, hip-hop, rock or jazz. I like pop music very much because I think it is gentle and suitable for teenagers. I listen to rock music when I am sad and after that I feel cheerful and happy. (3)________________ music from other countries is also good for teenagers to understand other cultures. (4)________ that, the lyrics are easy to understand and interesting. (5)________, it can improve my English and listening skills. (6)___________, music is an important part of my life and it helps me love my life more.

2. Read the passage and answer these questions below. (1point)

After retiring, my uncle – a lover of the sea- took up a strange leisure activity : he spends most mornings at the beach, looking for things that the sea sends ashore. He says: It’s a multi-beneficial leisure activity. I can get some exercise, blending, picking up, and walking. I can breathe the fresh air and enjoy the vastness and quietness of the sea. Sometimes I watch the children playing beach games and I feel years younger. At the same time, I can also clean the beach. It’s volunteer work, isn’t it? Many of the things I pick up from the beach are still useful to someone. I clean them and sell them at the Sunday flea market in the town nearby. Do you know of any leisure activity that pays? Mine does!

 

1. When did the writer’s take up this strange activity?

- ………………………………………………………………………………………..

2. Which part of the day does he go to the beach?

-………………………………………………………………………………………..

3. How does he feel watching the children playing beach games?

- ……………………………………………………………………………………….

4. What kind of volunteer work does he do?

-……………………………………………………………………………………..…

D-WRITING:

Question VI. Make sentences, using the words and phrases provided (1.5point)

1. Tippping/ not/ custom/ Viet Nam/ so/ you/ not/ have/ tip/ if/ don’t want.

………………………………………………………………………………………………

2. In Brazil/ standard/ tip/ in/ restaurant/ be 10 percent.

……………………………………………………………………………………………….

3. The xoe dance/ performed/ the boys and girls/ the hamlets.

………………………………………………………………………………………………

4. We/ have/take/ shoes/ when/ we/ inside/pagoda.

……………………………………………………………………………………………….

5.Nowadays/ teenagers/ rely/ technology/ than/ the/ past.

………………………………………………………………………………………………..

6.Life/ the countryside/ changed/ a lot/ the/ ten /years.

…………………………………………………………………………………………

 

ĐỀ SỐ 2

 

Question I. Find the word which has different sound in the part underlined. ( 1 point)                                                                                                                                           

1.         A. mention                 B. question                 C. action                     D. education

2.         A. listened                B. opened                      C. wanted                    D. lived

3.         A. community            B. computer                C. museum                 D. customs

4.         A. needed                  B. opened                      C. wanted                    D. decided

Question II. Choose the best answer A, B, C , or D to complete the sentences. (2. 5 points)                                                                                                                                           

1. You should ____________  information about a custom or tradition.

A. finds                              B. found                     C. finding          D. find

2. A tradition is something we do that is special and ____________ down through the generations.

A. to passed

B. passed

C. passing

D. is passing

3. In the UK, there are lots of customs for table manners. For example, We ____________ use

a knife and fork at dinner.

A. have to                     B. are having                    C. has to                          D. having to

4. In Viet Nam, you____________  use only the first name to  address people older than you.

A. should                        B. must                           C. shouldn’t                      D. have to

5. At the Mid-Autumn Festival ,kids can sing, dance, and enjoy moon-cakes ; ____________, every child likes it very much.

A. However            B. Moreover                            C. Because                        D. Therefore

6. In 2010, Ha Noi____________  its 1000th anniversary.

A. celebrated                  B. commemorated               C. worshipped                D. remembered

7. Tet is an occasion for family____________ in Viet Nam.

A. visitings               B. Meeting                    C. reunions                            D. seeings

8. ____________ spring comes, many Vietnamese villages prepare for a new festival season.

A. While                   B. When                      C. Nevertheless                      D. However

9. People burn incense to show respect to their ____________ during Tet.

A. relatives                  B. ancestors                      C. friends                      D. neighbors

10. The Le Mat Festival ____________ the founding of the village.

A. worships                  B. commemorates                      C. performs         D. preserves

Question III. Give the correct form of the following verbs: ( 2.0 points)

1. Peter  ____________ ________     football yesterday.                                                    (play)

 
 

2. When I came, the whole family  _________ _____ dinner around a big dining table.  (have)

3. Children should_____________  things from adults with both hands.                          (take)

4. My father and I __________   up at 5 o’clock every morning.                                     (get)

5. They  _________________ English at the moment.                                                     ( learn)

6.We   ____________________ to Hung King Festival since last Sunday.                        (go)

7. Before leaving the dinner table, _________your son ________ ask for permission?  (have to)

8.When I  ___________ ,the whole family was having dinner around a big dining table. (come)

 

Question IV. Choose the correct word for each blank in the following passage.( 3.0 points)

Spring is a time when there are many festivals in our country. Among them, Hoa Ban Festival is the most beautiful and interesting and it takes place in Lai Chau. It is typical of the (1)………life of the Thai people. In the second lunar month of the year, when it (2) ……..warmer and hoa ban - a kind of beautiful flower in the northwest mountainous area - blossoms, Hoa Ban Festival is (3)………... This is a great time for everyone, (4) …………… for boys and girls. The boy (4)………… the most beautiful flower and gives it to his girlfriend. This is not only a time for love but also for the Thai people to (5)………..for good crops, for happiness, and express their special thanks to the Gods and (6) …………... The festival is always full of songs and prayers.

  1. A .minor                     B. cultural                       C. custom                       D. festival

  2. A. gets                         B. goes                            C. comes                        D. runs

  3. A. seen                                    B. arranged                     C. observed                    D. celebrated

  4. A. largely                    B. especially                   C. generally                    D. typically

  5. A. ask                          B. look                            C. pray                            D. call

  6. A. fathers                    B. relatives                     C. families                       D. ancestors

Question V . Combine each pair of sentences to make one sentence, using the words given in brackets. 1.Lang Lieu couldn’t buy any special food . He was very poor.                 (BECAUSE)

…………………………………………………………………………………………..…..…

2.During Tet, Vietnamese people buy all kinds of sweets. They make Chung cakes as well.(SO)

…………………………………………………………………………………………..…..…

3.The Hung King Temple Festival was a local festival. It has become a public holiday in Viet Nam since 2007.(HOWEVER)

…………………………………………………………………………………………..…..…

 

16
20 tháng 2 2021

D-WRITING:

Question VI. Make sentences, using the words and phrases provided (1.5point)

1. Tippping/ not/ custom/ Viet Nam/ so/ you/ not/ have/ tip/ if/ don’t want.

…………………Tipping is not a custom in Viet Nam, so you don't have to tip if you don't want to.………………………………………

2. In Brazil/ standard/ tip/ in/ restaurant/ be 10 percent.

………………………………In Brazil, the standard tip in restaurants is 10 per cent.……………………………….

3. The xoe dance/ performed/ the boys and girls/ the hamlets.

……………………The xoe dance was performed by the boys and the girls in the hamlets.……………………………………………

4. We/ have/take/ shoes/ when/ we/ inside/pagoda.

……………………We have to take oà your shoes when we go inside a pagoda.……………………………………….

5.Nowadays/ teenagers/ rely/ technology/ than/ the/ past.

…………………………Nowadays teenagers rely on technology more than in the past.……………………………..

6.Life/ the countryside/ changed/ a lot/ the/ ten /years.

………………………Life in the countryside has changed a lot over the past ten years.………………………………

20 tháng 2 2021

ĐỀ SỐ 2

 

Question I. Find the word which has different sound in the part underlined. ( 1 point)                                                                                                                                           

1.         A. mention                 B. question                 C. action                     D. education

2.         A. listened                B. opened                      C. wanted                    D. lived

3.         A. community            B. computer                C. museum                 D. customs

4.         A. needed                  B. opened                      C. wanted                    D. decided

Question II. Choose the best answer A, B, C , or D to complete the sentences. (2. 5 points)                                                                                                                                           

1. You should ____________  information about a custom or tradition.

A. finds                              B. found                     C. finding          D. find

2. A tradition is something we do that is special and ____________ down through the generations.

A. to passed

B. passed

C. passing

D. is passing

3. In the UK, there are lots of customs for table manners. For example, We ____________ use

a knife and fork at dinner.

A. have to                     B. are having                    C. has to                          D. having to

4. In Viet Nam, you____________  use only the first name to  address people older than you.

A. should                        B. must                           C. shouldn’t                      D. have to

5. At the Mid-Autumn Festival ,kids can sing, dance, and enjoy moon-cakes ; ____________, every child s it very much.

A. However            B. Moreover                            C. Because                        D. Therefore

6. In 2010, Ha Noi____________  its 1000th anniversary.

A. celebrated                  B. commemorated               C. worshipped                D. remembered

7. Tet is an occasion for family____________ in Viet Nam.

A. visitings               B. Meeting                    C. reunions                            D. seeings

8. ____________ spring comes, many Vietnamese villages prepare for a new festival season.

A. While                   B. When                      C. Nevertheless                      D. However

9. People burn incense to show respect to their ____________ during Tet.

A. relatives                  B. ancestors                      C. friends                      D. neighbors

10. The Le Mat Festival ____________ the founding of the village.

A. worships                  B. commemorates                      C. performs         D. preserves

Question III. Give the correct form of the following verbs: ( 2.0 points)

1. Peter  ____________played ________     football yesterday.                                                    (play)

 
 

2. When I came, the whole family  _________was having _____ dinner around a big dining table.  (have)

3. Children should______take_______  things from adults with both hands.                          (take)

4. My father and I ___get_______   up at 5 o’clock every morning.                                     (get)

5. They  ______are learning___________ English at the moment.                                                     ( learn)

6.We   ______________went______ to Hung King Festival since last Sunday.                        (go)

7. Before leaving the dinner table, _____does____your son _____have to___ ask for permission?  (have to)

8.When I  _____came______ ,the whole family was having dinner around a big dining table. (come)

 

Ex1: Choose the best answer:Question 1: Do you know what is the cause __________ pollution?A. of            B. in       C. on      D. forQuestion 2: My mother has to measure blood __________ every monthA. billboard        B. pressure C. groundwater D. earplugQuestion 3: __________ pollution is harmful or annoying level of noise, as from vehicles, industry activities, etc.A. light        B. visual C. soil D. noiseQuestion 4: Parents should teach children not to...
Đọc tiếp

Ex1: Choose the best answer:

Question 1: Do you know what is the cause __________ pollution?

A. of            B. in       C. on      D. for

Question 2: My mother has to measure blood __________ every month

A. billboard        B. pressure C. groundwater D. earplug

Question 3: __________ pollution is harmful or annoying level of noise, as from vehicles, industry activities, etc.

A. light        B. visual C. soil D. noise

Question 4: Parents should teach children not to __________ wastes on the road

A. litter        B. poison C. cause D. measure

Question 5: I can’t hear your voice __________ I’m wearing an earplug

A. although        B. due C. however D. because

Question 6: His grandfather made him __________ hard when he was small

A. study        B. to study C. studying D. studied

Question 7: This picture __________ the contamination of ground water.

A. illustrate        B. illustrating C. illustrates D. illustrated

Question 8: Could you list some non-point source __________?

A. pollution        B. pollutants C. polluting D. polluted

Question 9: Scientists has just come up __________ a solution to hearing loss

A. to            B. on C. with D. down

Question 10: If we dump a plastic into the ground, it __________ a long time to disappear.

A. will take        B. take C. took D. takes

Question 11: Pollutions are harmful __________ human health

A. with        B. at C. to D. on

Question 12: __________ water resulted in the death of many aquatic animals.

A. Contaminate    B. Contaminated C. Contaminating D. Contamination

Question 13: What would you do if a factory in your neighborhood __________ untreated water into the river?

A. dump        B. dumped C. dumping D. dumps

Question 14: Have you ever heard about the __________ of radioactive pollution?

A. affects        B. effects C. pollutes D. poisons

Question 15: : __________ pollution is the increase of temperature caused by human activity.

A. visual        B. water C. thermal D. radioactive

Ex2: Supply the correct form of the verbs in brackets

1. Lan often (do) __________ her homework.

2. They (play) __________ tennis now.

3. Lan (buy) _________ a car since 2000.

4. Minh (watch) _______ TV last night.

5. Hoa (meet) _________ Lan tomorrow.

6. Football (play) ________ by boys.

Ex3: Find and correct mistakes:

1.What about watch TV?

 A. What        B. about        C. watch

2.Do you mind if I listened to music?

 A. mind        B. listened        C. to

3.What do you do yesterday?

A. What        B. do            C. yesterday

4.My dog is different with her dog.

A. is            B. with        C. her

Ex4: Rewrite sentences without changing the meaning.

1. Let’s go to the zoo!

What about .......................................................................?

2. Ba enjoys skipping.

Ba likes ..............................................................................

3. Long should work harder.

Long ought to ....................................................................

4. Would you mind opening the door?

Do you mind ......................................................................?

4. I can’t tell you unless you tell me what’s wrong. (if)

-> …………………………………………………………

5. Nhung didn’t go to the cinema with her friends because her younger sister was ill.

-> Because of …… 

6. Eating too much sugar can result in health problem. (lead to)

-> …………………………………………………………………

7. Minh isn’t hard working, so he often gets bad marks. (if)

-> …………………………………………………………

8. I’m not you. But I think you should recycle these plastic carrier bags. (If)

-> …………………………………………………………

Ex5: Use the correct form of the words given to complete the sentences.

1. This volcano is dead; it has been (ACT) _____ for more than a century.

2. The Earth would be a happy planet if human beings, animals and plants (PEACE) _____ co-existed.

3. The chemical (POLLUTE) _____from cars and factories make the air, water and soil dangerously dirty.

4. You cannot imagine how (SERIOUS) _____the area was damaged by the flood.

5.  Scotland is a ……….. land and this is noted for its rich and interesting history. (legend)

5

Ex1: Choose the best answer:

Question 1: Do you know what is the cause __________ pollution?

A. of            B. in       C. on      D. for

Question 2: My mother has to measure blood __________ every month

A. billboard        B. pressure C. groundwater D. earplug

Question 3: __________ pollution is harmful or annoying level of noise, as from vehicles, industry activities, etc.

A. light        B. visual C. soil D. noise

Question 4: Parents should teach children not to __________ wastes on the road

A. litter        B. poison C. cause D. measure

Question 5: I can’t hear your voice __________ I’m wearing an earplug

A. although        B. due C. however D. because

Question 6: His grandfather made him __________ hard when he was small

A. study        B. to study C. studying D. studied

Question 7: This picture __________ the contamination of ground water.

A. illustrate        B. illustrating C. illustrates D. illustrated

Question 8: Could you list some non-point source __________?

A. pollution        B. pollutants C. polluting D. polluted

Question 9: Scientists has just come up __________ a solution to hearing loss

A. to            B. on C. with D. down

Question 10: If we dump a plas into the ground, it __________ a long time to disappear.

A. will take        B. take C. took D. takes

Question 11: Pollutions are harmful __________ human health

A. with        B. at C. to D. on

Question 12: __________ water resulted in the death of many aqua animals.

A. Contaminate    B. Contaminated C. Contaminating D. Contamination

Question 13: What would you do if a factory in your neighborhood __________ untreated water into the river?

A. dump        B. dumped C. dumping D. dumps

Question 14: Have you ever heard about the __________ of radioactive pollution?

A. affects        B. effects C. pollutes D. poisons

Question 15: : __________ pollution is the increase of temperature caused by human activity.

A. visual        B. water C. thermal D. radioactive

Ex2: Supply the correct form of the verbs in brackets

1. Lan often (do) ____does______ her homework.

2. They (play) ______are playing____ tennis now.

3. Lan (buy) ___has bought______ a car since 2000.

4. Minh (watch) ___watched____ TV last night.

5. Hoa (meet) ____will meet_____ Lan tomorrow.

6. Football (play) _____is played___ by boys.

20 tháng 2 2021

Chào em, em tham khảo nhé!

Ex3: Find and correct mistakes:

1.What about watch TV?

 A. What        B. about        C. watch => watching

2.Do you mind if I listened to music?

 A. mind        B. listened => listen        C. to

3.What do you do yesterday?

A. What        B. do => did           C. yesterday

4.My dog is different with her dog.

A. is            B. with => from        C. her

Ex4: Rewrite sentences without changing the meaning.

1. Let’s go to the zoo!

What about going to the zoo?

2. Ba enjoys skipping.

Ba s skipping/to skip.

3. Long should work harder.

Long ought to work harder.

4. Would you mind opening the door?

Do you mind opening the door?

4. I can’t tell you unless you tell me what’s wrong. (if)

-> If you don't tell me what's wrong, I can't tell you.

5. Nhung didn’t go to the cinema with her friends because her younger sister was ill.

-> Because of her illness, Nhung didn't go to the cinema with her friends.

6. Eating too much sugar can result in health problem. (lead to)

-> Eating too much sugar can lead to health problem.

7. Minh isn’t hard-working, so he often gets bad marks. (if)

-> If Minh were hard-working, he wouldn't get bad marks.

8. I’m not you. But I think you should recycle these plas carrier bags. (If)

-> If I were you, I would recycle these plas carrier bags.

Ex5: Use the correct form of the words given to complete the sentences.

1. This volcano is dead; it has been (ACT) inactive for more than a century.

2. The Earth would be a happy planet if human beings, animals and plants (PEACE) peacefully co-existed.

3. The chemical (POLLUTE) pollutant from cars and factories make the air, water and soil dangerously dirty.

4. You cannot imagine how (SERIOUS) serious the area was damaged by the flood.

5.  Scotland is a legendary land and this is noted for its rich and interesting history. (legend)

Chúc em học tốt và có những trải nghiệm tuyệt vời tại olm.vn!

20 tháng 2 2021

Do (SAB) và (SAC) vuông góc với đáy (ABC)

Và (ABC) ∩ (SAC) = SA nên SA ⊥ (ABC)

BC ⊥ AH, BC ⊥ SA

⇒ BC ⊥ ((SAH)

Mà BC ⊂ (SBC) nên (SAH) ⊥ (SBC)

20 tháng 2 2021
SAB và SAC vuông góc với ABC Và (ABC ) (SAC) =SA nên SA vuông góc BC vuông góc với AH .BC vuông góc SA Mà BC (ABC)nên (SAH) vuông góc ABC BC vuông góc SAH
Đọc văn bản sau và thực hiện các yêu cầu bên dưới:THỜI GIAN LÀ VÀNG          Ngạn ngữ có câu: Thời gian là vàng. Nhưng vàng thì mua được mà thời gian không mua được. Thế mới biết vàng có giá mà thời gian là vô giá.          Thật vậy, thời gian là sự sống. Bạn vào bệnh viện mà xem, người bệnh nặng, nếu kịp thời chạy chữa thì sống, để chậm là chết.         ...
Đọc tiếp

Đọc văn bản sau và thực hiện các yêu cầu bên dưới:

THỜI GIAN LÀ VÀNG

          Ngạn ngữ có câu: Thời gian là vàng. Nhưng vàng thì mua được mà thời gian không mua được. Thế mới biết vàng có giá mà thời gian là vô giá.

          Thật vậy, thời gian là sự sống. Bạn vào bệnh viện mà xem, người bệnh nặng, nếu kịp thời chạy chữa thì sống, để chậm là chết.

          Thời gian là thắng lợi. Bạn hỏi các anh bộ đội mà xem, trong chiến đấu, biết nắm thời cơ, đánh địch đúng lúc là thắng lợi, để mất thời cơ là thất bại.

          Thời gian là tiền. Trong kinh doanh, sản xuất hàng hóa đúng lúc là lãi, không đúng lúc là lỗ.

          Thời gian là tri thức. Phải thường xuyên học tập thì mới giỏi. Học ngoại ngữ mà bữa đực, bữa cái, thiếu kiên trì, thì học mấy cũng không giỏi được.

          Thế mới biết, nếu biết tận dụng thời gian thì làm được bao nhiêu điều cho bản thân và cho xã hội. Bỏ phí thời gian thì có hại và về sau hối tiếc cũng không kịp.

(Phương Liên,.. NXB Giáo dục)

Câu 1:  Xác định phương thức biểu đạt chính được sử dụng trong văn bản.

Câu 2: Văn bản trên nêu tư tưởng gì? Tư tưởng đó thể hiện trong những luận điểm nào? Liệt kê những câu mang luận điểm.

Câu 3: Văn bản có bố cục mấy phần, hãy chỉ ra cách lập luận được sử dụng trong bài.

Câu 4Qua Văn bản trên, em rút ra bài học gì về việc sử dụng thời gian?

Câu 5( Nâng cao): Thông điệp nào của văn bản trên có ý nghĩa nhất em? Vì sao?

Câu 6( Nâng cao): Viết đoạn văn khoảng 7-10 dòng trình bày suy nghĩ của em về câu: Bỏ phí thời gian thì có hại và về sau hối tiếc cũng không kịp.

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20 tháng 2 2021
Ex1: Choose the best answer: Question 1: Do you know what is the cause __________ pollution? A. of            B. in       C. on      D. for Question 2: My mother has to measure blood __________ every month A. billboard        B. pressure C. groundwater D. earplug Question 3: __________ pollution is harmful or annoying level of noise, as from vehicles, industry activities, etc. A. light        B. visual C. soil D. noise Question 4: Parents should teach children not to __________ wastes on the road A. litter        B. poison C. cause D. measure Question 5: I can’t hear your voice __________ I’m wearing an earplug A. although        B. due C. however D. because Question 6: His grandfather made him __________ hard when he was small A. study        B. to study C. studying D. studied Question 7: This picture __________ the contamination of ground water. A. illustrate        B. illustrating C. illustrates D. illustrated Question 8: Could you list some non-point source __________? A. pollution        B. pollutants C. polluting D. polluted Question 9: Scientists has just come up __________ a solution to hearing loss A. to            B. on C. with D. down Question 10: If we dump a plastic into the ground, it __________ a long time to disappear. A. will take        B. take C. took D. takes Question 11: Pollutions are harmful __________ human health A. with        B. at C. to D. on Question 12: __________ water resulted in the death of many aquatic animals. A. Contaminate    B. Contaminated C. Contaminating D. Contamination Question 13: What would you do if a factory in your neighborhood __________ untreated water into the river? A. dump        B. dumped C. dumping D. dumps Question 14: Have you ever heard about the __________ of radioactive pollution? A. affects        B. effects C. pollutes D. poisons Question 15: : __________ pollution is the increase of temperature caused by human activity. A. visual        B. water C. thermal D. radioactive Ex2: Supply the correct form of the verbs in brackets 1. Lan often (do) __________ her homework. 2. They (play) __________ tennis now. 3. Lan (buy) _________ a car since 2000. 4. Minh (watch) _______ TV last night. 5. Hoa (meet) _________ Lan tomorrow. 6. Football (play) ________ by boys. Ex3: Find and correct mistakes: 1.What about watch TV?  A. What        B. about        C. watch 2.Do you mind if I listened to music?  A. mind        B. listened        C. to 3.What do you do yesterday? A. What        B. do            C. yesterday 4.My dog is different with her dog. A. is            B. with        C. her Ex4: Rewrite sentences without changing the meaning. 1. Let’s go to the zoo! What about .......................................................................? 2. Ba enjoys skipping. Ba likes .............................................................................. 3. Long should work harder. Long ought to .................................................................... 4. Would you mind opening the door? Do you mind ......................................................................? 4. I can’t tell you unless you tell me what’s wrong. (if) -> ………………………………………………………… 5. Nhung didn’t go to the cinema with her friends because her younger sister was ill. -> Because of ……  6. Eating too much sugar can result in health problem. (lead to) -> ………………………………………………………………… 7. Minh isn’t hard working, so he often gets bad marks. (if) -> ………………………………………………………… 8. I’m not you. But I think you should recycle these plastic carrier bags. (If) -> ………………………………………………………… Ex5: Use the correct form of the words given to complete the sentences. 1. This volcano is dead; it has been (ACT) _____ for more than a century. 2. The Earth would be a happy planet if human beings, animals and plants (PEACE) _____ co-existed. 3. The chemical (POLLUTE) _____from cars and factories make the air, water and soil dangerously dirty. 4. You cannot imagine how (SERIOUS) _____the area was damaged by the flood. 5.  Scotland is a ……….. land and this is noted for its rich and interesting history. (legend)
Bài 1:a. Dòng sông Năm Căn mênh mông, nước ầm ầm đổ ra biển ngày đêm như thác, cá nước bơi hàng đàn đen trũi nhô lên hụp xuống như người bơi ếch giữa những đầu sóng trắng. Thuyền xuôi giữa dòng con sông rộng hơn ngàn thước, trông hai bên bờ, rừng đước dựng lên cao ngất như hai dãy trường thành[8] vô tận.                             (Sông nước Cà Mau - Đoàn Giỏi)b.Thuyền...
Đọc tiếp

Bài 1:

a. Dòng sông Năm Căn mênh mông, nước ầm ầm đổ ra biển ngày đêm như thác, cá nước bơi hàng đàn đen trũi nhô lên hụp xuống như người bơi ếch giữa những đầu sóng trắng. Thuyền xuôi giữa dòng con sông rộng hơn ngàn thước, trông hai bên bờ, rừng đước dựng lên cao ngất như hai dãy trường thành[8] vô tận. 

                            (Sông nước Cà Mau - Đoàn Giỏi)

b.Thuyền xuôi giữa dòng con sông rộng hơn ngàn thước, trông hai bên bờ, rừng đước dựng lên cao ngất như hai dãy trường thành vô tận. Cây đước mọc dài theo bãi, theo từng lứa trái rụng, ngọn bằng tăm tắp, lớp này chồng lên lớp kia ôm lấy dòng sông, đắp từng bậc màu xanh lá mạ, màu xanh rêu, màu xanh chai lọ,... loà nhoà ẩn hiện trong sương mù và khói sóng ban mai. 

                                             (Sông nước Cà Mau - Đoàn Giỏi)

Bài 2: Bài học em có được sau khi học văn bản "Bài học đường đời đầu tiên"?

Bài 3: Tìm trong văn bản "Vượt thác" những hình ảnh so sánh? Nêu tác dụng của một phép so sánh?

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20 tháng 2 2021

chịu đã lên lớp 6đâu mà hỏi nguời ta hả

20 tháng 2 2021

Bài 2.Từ văn bản "Bài học đường đời đầu tiên", em rút ra được bài học cho mình là:
- Bài học về tính kiêu căng, hỡm hĩnh, xốc nổi của Dế Mèn.
- Bài học về lòng bao dung độ lượng, biết cảm thông và tha thứ của Dế Choắt.
- Bài học về cách biết kiềm chế, không nên nóng nảy, tự ái của chị Cốc.
- Bài học về lòng nhân ái, biết yêu thương giúp đỡ những người yếu hơn mình.

Bài 3a. 

  • Những câu văn có sử dụng phép so sánh trong bài thơ Vượt thác là:

“Thuyền rẽ sông lướt bon bon như đang nhớ núi rừng phải lướt cho nhanh để về cho kip.”

“ Những động tác thả sào, rút sào rập ràng nhanh như cắt.”

“Dượng Hương Thư như một pho tượng đồng đúc, các bắp thị cuồn cuộn, hai hàm răng cắn chặt, quai hàm bạnh ra, cặp mắt nảy lửa ghì trên ngọn sào giống như một hiệp sĩ của Trường Sơn oai linh hùng vĩ."

"Dọc sườn núi, những cây to mọc giữa những bụi lúp xúp nom xa như những cụ già vung tay hô đám con cháu tiến về phía trước."

20 tháng 2 2021

SA vg (ABC)=> SAB,SAC vuông

SA vg BC, AB vg BC => BCvg (SAB) =>SB vg BC=> SBC vuông

vậy all mặt đều vuông

21 tháng 2 2021

\(\hept{\begin{cases}SA\perp\left(ABC\right)\\AB\subset\left(ABC\right)\end{cases}}\) \(\Rightarrow SA\perp AB\Rightarrow\)    tam giác SAB vuông (1) 

\(\hept{\begin{cases}SA\perp\left(ABC\right)\\AC\subset\left(ABC\right)\end{cases}\Rightarrow AC\perp SA\Rightarrow}\)    tam giác SAC vuông (2) 

Tam giác ABC vuông tại B (gt) (3) 

\(\Rightarrow AB\perp BC\)   

\(\hept{\begin{cases}SA\perp\left(ABC\right)\\BC\subset\left(ABC\right)\end{cases}\Rightarrow SA\perp BC}\)    

\(\hept{\begin{cases}AB\perp BC\\SA\perp BC\end{cases}\Rightarrow\hept{\begin{cases}BC\perp\left(SAB\right)\\SB\subset\left(SAB\right)\end{cases}\Rightarrow}SB\perp BC\Rightarrow}\)    Tam giác SBC vuông (4) 

 \(\left(1\right);\left(2\right);\left(3\right);\left(4\right)\Rightarrowđpcm\)