- Unit 1 The Changing World
- Unit 2 Saving the Earth
- 1. Popullution has caused too many problems.
- 2. All these problems are very serious.
- 3. What can we do at home to protect the environment?
- Review of Units 1—2
- Unit 3 English Around the World
- Unit 4 Amazing Science
版本：
很抱歉，暂时没有该知识点下的试题，等待我们的收集吧o(╥﹏╥)o