Bài 1: Sửa lỗi sai.
1. Scientists have tried to asses the impact of human activities on the environmental.
2. Ann asked Kirk if had he really written that story the previous day.
3. If I passed this exam, I'll go to the university next summer.
4. All new workers mustn't have a medical examination.
5. The chemical pollutants from cars and factories make the air, water, and soil dangerously dirtily.
6. Do you remember a name of the hotel which is at the end of this street?
7. He works at Heathrow Airport, that is one of the biggest airport in the world.