Unit 1 The Changing World

• 1. Our country has developed rapidly.

• 2. The population in developing countries is growing faster.

• 3. The world has changed for the better.

Review of Unit 1

Unit 2 Saving the Earth

• 1. Pollution 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

• 1. English is widely spoken throughout the world.

• 2. Some things usually have different meanings in different cultures.

• 3. Could you give us some advice on how to learn English well?

Review of Unit 3

Unit 4 Amazing Science

• 1. When was it invented?

• 2. I'm excited about the things that will be discovered in the future.

• 3. China is the third nation that sent a person into space.

Review of Units 3—4

综合复习与测试