while she______(cry), a fairy appeared

students over fifteen might______ (bring) a phone to school

1. If I (be) the president, I (pass) harder regulations for using fertilizers in agriculture.

2. If I (be) you, I (not eat) that genetically modified potatoes.

3. If big corporations (care) more about the environment and less about their own pockets, the pollution from factories (not increase) so fast.

4. He (sort) his trash, if he (be) smart.

5. If the seas (pollute) , maybe the population of whales (recover) .

6. If I (not throw) this can of Coke into the bushes, I (not know) that Coke is poison for wild animals.

7. If the factories (not dump) untreated waste into the ocean, fish (die) massively.

8. What (do) you if you (be) President.

9. If the air (not be) dirty, the breathing problems (reduce) .

10. If I (own) a lonely island, I (build) a huge house by the beach.

Bài 1. Tính % khối lượng các nguyên tố có trong các phân tử sau:

a)    CO; MgCl₂; C₆H₆.

b)    FeO; Fe₃O₄;

c)     CuSO₄; CaCO₃

Người xưa có câu: ''Trúc dẫu cháy, đốt ngay vẫn thẳng''

Dấu ngoặc kép có tác dụng gì