1. Pollution is a topic of such important today that even elementary school children are well-informed about its danger.
A. its B. well-informed C. Pollution D. important (chọn từ nào sai nhen).
2. Your help was greatly .......................
A. appreciation B. appreciated C. appreciative D. appreciating
* Câu này em nghĩ là cần tính từ và nói về vật nên là D mà ko biết đúng ko?
3. Jim and Paul were the two men ………… on Mr. Smith’s roof.
A. worked B. to work C. work D. who were working
4. Rain forest are places_____ people harvest wood, delicious fruits, and powerful medicine.
A. in which B. in that C. in where D. which
* chọn và giải thích.