Cho tam giác ABC vuông tại A, đường cao AH. Kẻ HM vuông góc AB, HN vuông góc với AC (M thuộc AB, N thuộc AC)

a) Tứ giác AMHN là hình gì? Vì sao?

b) Lấy D đối xứng với H qua M, lấy E đối xứng với H qua N. Chứng minh rằng: 3 điểm D, A, E thẳng hàng.

Cho tam giác ABC vuông tại A (AB<AC), đường cao AD.Gọi E và F lần lượt là hình chiếu của D trên AB,AC.Lấy G là trung điểm AC,H là trung điểm DC.Chứng minh rằng
a,Tứ giác AEDF là hcn
b,Gọi I là giao điểm của EF và AD.Chứng minh rằng tứ giác IHCG là hình bình hành
c,Trên tia đối tia DE,lấy điểm K sao cho DK=AC.Chứng minh rằng CK song song AD
d,Chứng minh I là trực tâm của Tam giác HAB

Cứu tui đi

3 Complete the sentences with much or slightly and the comparative form to describe the difference.
1 Sumo competitors can weigh more than 200kg. They're (heavy) than most athletes.
2 Our players are (short) than professional players. The difference is not significant.
3 American football is (aggressive) than soccer or other ball sports. Players get seriously injured in games.
4 The rules of soccer are (easy) than the rules of rugby. After watching just a couple of matches, you can understand the rules of the game.

Many people enjoy living in a big city because the think life in city is more exciting there. However, I come from small village and in my viewpoint, there are lots of benefits. The main reson I prefer village life is because it is very quiet, i can wake up by listening to the sound of birds singing on trees in the early morning. Another reason is that the air is so fresh and clean. We have more green spaces and bigger garden, too. The climate is warm and wet, which is great for growing rice, herding cattle, milking cows and plouding fields. Moreever, I think people here are friendly and kin. Countries are smaller communities and often evryone knows very well, so you might not have the next door neighbour, but you will have a handful of people who support and help each other. The " nón lá ", or rice hats. are often worn by framers to protect their heads from the sun. Because so many framers wear nón lá, they have become a symbol of Vietnam.

25. Life in the country is better than in the city          True or False

26. The atmosphere in the countryside is peaceful    True or False

27. In author's opinion, people in the countryside sre hospitable and ready to help each other       True or Flase

28. The "nón lá" is useful to farmers and very famous in Vietnam                 True or False

4.Mongolian children learn to ride when they are _______  as three year old .

     A. as young     B. younger    C. younger than        D. so young

5. Countryside is not pollued ______ you can breathe there fresh air.

    A.   although     B.however     C.therefore               D.  as

6.'Children in my village often fly their kites in the paddy field.' '______' 

   A . I'm glad you like it      B.  that's awesome 

   C .How interesting           D.Exactly what I want

7._______fied is a fied planted with rice growing in water.

A.Paddy          B.Grass           C.  Grain             D.Good

8. After harvesting rice,the farmers often______it in the sunlight.

A .Collect        B. weather        C . dry pick               D.pick

9. His neighbours helped him_______a cattle station outside his house. 

 A.  road       B.putup             C.  load              D .herd

  -giúp mình với