Unit 1 The Changing World 1
Topic 1 China has developed rapidly in recent years 1
Topic 2 What has happened to the population? 7
Topic 3 The world has changed for the better 13
单元评价我巩固 18
Unit 2 Saving the Earth 22
Topic 1 I can't stand the environment here 22
Topic 2 How does pollution hurt the earth? 28
Topic 3 Let's be the greener people 34
单元评价我巩固 40
Unit 3 English around the World 43
Topic 1 English is widely spoken around the world 43
Topic 2 English is spoken differently in different countries 48
Topic 3 It's important to learn English well 53
单元评价我巩固 59
Unit 4 Fantastic Science 62
Topic 1 The spaceship is so magical! 62
Topic 2 When was it invented? 68
Topic 3 Perhaps people will fly to Mars 73
单元评价我巩固 78
期中评价我提高 81
期末评价我前进 85
参考答案 89