前辅文 Unit 1 Caring for Our Earth Unit 2 Nobel Prize Winners Unit 3 Famous Brand Names Unit 4 Cloning and Ethics Self-assessment Test (Unit 1 — Unit 4) Unit 5 Lifelong Education Unit 6 Travel Around the World Unit 7 Drug Abuse Unit 8 Conflicts in the World Self-assessment Test (Unit 5 — Unit 8) Key to Exercises Tapescripts
