B1:

1. If we recycle,we'll save natural resouces.
2. If you aren't careful,you'll fall over the rocks.

3. If he buy recycled products, he can do a part to save the environment

4. If we put garbage into the bins, we will minimize pollution.
5. If you work too much,you can feel tired.

6. If the authorities are thinking of rising petrol prices, it will have to cycle to work.
7. If you are careless,you'll break the vase.
8. If Chris hasn't to work hard, she will pass the exam

9. If Allen give it back next week, she can borrow it

10. We will get lost our way in the forest if we don't take the map with us 

B2: 

1. worried

2. complaint

3. deforestation

4. pollution

5. clearly

6. died

7. suggestion

8. disapointed

9. politely

10. conservationists

11. refreshment

12. preservation

13. seriously

14. choose

mk k bt có đúng hết k đâu nhaa nhưng đại khái là đúng (mk nghĩ tek) :>