Unit 1 Caring for Our Earth 1
Unit 2 Nobel Prize Winners 9
Unit 3 Famous Brand Name 19
Unit 4 Cloning and Ethics 28
Self-assessment Test(Unit 1—Unit 4) 37
Unit 5 Life-long Education 47
Unit 6 Travel Around the World 56
Unit 7 Drug Abuse 65
Unit 8 Conflicts in the World 74
Self-assessment Test(Unit 5—Unit 8) 83