Unit 1 The Developing World 1
Topic 1 Our country has developed rapidly 1
Topic 2 What a large population! 8
Topic 3 The world has changed for the better 15
Unit 2 Loving Our Planet 22
Topic 1 Pollution causes too many problems 22
Topic 2 All these problems are very serious 29
Topic 3 Would you like to be a greener person? 35
Review of Units 1-2 41
Unit 3 English Around the World 45
Topic 1 English is widely used throughout the world 45
Topic 2 English is spoken differently in different countries 52
Topic 3 Could you give us some advice on how to learn English well? 59
Unit 4 Amazing Science 66
Topic 1 Spaceships are mainly controlled by computers 66
Topic 2 When was it developed? 73
Topic 3 We will live in space one day 80
Review of Units 3-4 87
参考答案 92