6. Because the climate is changing, the earth is getting warmer

7. Unless we stop cutting down so many trees, we endanger our oxygen supply

8. When people begin to recycle, they generate much less trash

9. Even though the ozone layer is necessary for human existence, we are damaging the ozone layer

10. Sue was exposed to radiation when she was young so she is suffering from skin cancer

`=>` Unless `=` If … not …

`=>` If bằng When / Whenever

`-` Áp dụng :

`-` Câu trúc điều kiện loại 0:

`=>` If + S + V (-s / -es), S + V (-s / -es)

`-` Câu trúc điều kiện loại 1:

`=>`  If + S + V (am/is/are, -s/-es), S + will/can/must/might…+ V-bare

6. The climate is changing. The earth is getting warmer

-> Because the climate is changing, the earth is getting warmer

Because S + V, S + V : Bởi vì 

7. We should stop cutting down so many trees. We endanger our oxygen supply

-> Unless we stop cutting down so many trees, we won't endanger our oxygen supply

Unless = If not + Trừ khi 

8. People begin to recycle. They generate much less trash

-> When people begin to recycle, they generate much less trash

When = Khi 

9. We are damaging the ozone layer. The ozone layer is necessary for human existence

-> We are damaging the ozone layer even though it is necessary for human existence

Even though = Although = mặc dù

Even though S + V, S + V

10. Sue is suffering from skin cancer. She was exposed to radiation when she was young

-> Sue was exposed to radiation when she was young so she is suffering from skin cancer

so = vì thế 

S + V so S + V