Unit 1 Changes in the Way We Live 1
Unit 2 Civil-Rights Heroes 12
Unit 3 Security 24
Unit 4 Extraterrestrials 34
Unit 5 How to Celebrate Holidays 45
Unit 6 The Human Touch 55
Unit 7 Making a Living 64
Unit 8 Cloning 75
Appendix Ⅰ:Key to Exercises(Units 1-8) 87
Appendix Ⅱ:Chinese Translations of Texts A(Units 1-8) 144
Appendix Ⅲ:Chinese Translations of Texts B(Units 1-8) 167