=>
III/
1. fascinating
2. variation 
3. polluting
4. thoughtfully
5. imaginary
6. impressive
7. underdeveloped
8. competitive
9. contribution
10. environmentalists 

IV/
1. I am interested in reading detective stories.
2. In order to see the Golden Gate Bridge, they went to San Francisco.
3. Unless the working conditions are improved, the worker will stop working.
4. It was until my father came home from work that we had dinner.
5. He'd like to be an architect like his father.
6. If Tom hadn't fallen asleep while driving, he wouldn't have crashed his car.
7. The late which has a variety of fish is at the foot of the hill.
8. A new hospital is going to be built for children.
9. Don't forget to turn off the lights before you go to bed.
10. On their return from the trip, they discovered their house had been broken into by thieves.

III/
1. fascinating-adj
2. variety-n
vì có "the"; the+N
3. polluting-v
thì hiện tại tiếp diễn
4. to think
wrinkled his brow to think= V+O+to V
5. to imagine
6. impressive-adj
7. developing-adj
developing countries: các đất nước đang phát triển
8. competitive-adj
a/an+adj+N
9. contribution-n
dùng danh từ vì sau có "positive"-adj: adj+N
10. environmentalists-n
of+N; sau giới từ đi với danh từ
****************
1. I am interested in reading detective stories.

2. In order to see the Golden Gate Bridge, they went to San Francisco.

3. Unless the working conditions improved, the workers will stop working. 
-Unless=If..not...

4. It was not until my father came home from work, we have dinner.
-> Mãi cho đến khi bố tôi đi làm về, chúng tôi mới ăn tối. 

5. He'd like to be an architect like his father. 
'd like= would like+to V

6. If Tom hadn't fallen asleep while driving, he wouldn't have crashed his car.
-câu đk loại 3, vì câu đề bài dùng thì QKĐ

7. The lake which has a variety of fish is at the foot of the hill.

8. A new hospital is going to be built for children.
-Bị động: be going to be+P.P

9. Don't forget to turn off the lights before you go to bed.
->  Đừng quên tắt đèn trước khi đi ngủ.= Hãy nhớ tắt đèn trước khi đi ngủ.