Book 1
Unit 1 Getting along with others 1
Book 6
Unit 2 The environment 33
Unit 3 Science versus nature 64
期中自测题 91
Unit 1 Laughter is good for you 103
Unit 2 What is happiness to you? 134
Unit 3 Understanding each other 166
Unit 4 Helping people around the world 195
期末自测题 223
答案与提示 235