Bài 6. Hoàn thành các câu sau, chọn và cho dạng đúng của các động từ cho sẵn.

1. If we use less vehicles, we _________ the amount of carbon dioxide into the air.

2. If you __________ the president, what you do to prevent air pollution.

3. If there were no fresh water left, what ____?

4. If people (not) ________________ rubbish in the street, it would look better.

5. if there wasn’t so much light in the cities at night, we __________ the starts more clearly.

6. If the water is contaminated, people ________ from many diseases.

7. If chemicals from factories are dumped into rivers and lakes, they ______ water pollution.

8. If people want to protect their planet, they should ________ their habit of using plastic bag for convenience.

9. If we recycle paper, we ________ 1000 trees a day.

10. If people were more aware of the negative consequences of pollution, they might ______ actions to prevent it.

Cho hình thang ABCD(AB//CD). Gọi O là giao điểm của hai đường chéo AC và BD.

a) Tính CD,Chứng minh rằng OA.OD = OB.OC.

b) Đường thẳng qua O vuông góc với AB và CD theo thứ tự tại H và K.Tính\(\frac{OH}{OK}\)

What do you say in these situations? Write the sentences, using imperatives.
Here is an example.
0. Your friends are making a lot of noise, and you want them to stop.
Answer: 0. Please, stop making noise.
1. The cat is scratching the carpet, and you want it to stop.
_____________________________________________
2. The teacher wants her students to close their books.
_____________________________________________
3. The teacher reminds students to do homework.
_____________________________________________
4. The mother tells the boy to bring his umbrella.
_____________________________________________
5. You tell your friend not to copy your homework.
_____________________________________________

Tính:

1+1=2

2nha bn

2^2 . 2^3 . 4^0 + 0 : (54 + 46)

= 2^5 . 1 + 0

= 32 + 0

= 32.