Unit 11 Scientific achievements 1
Unit 12 Fact and fantasy 16
Unit 13 The water planet 31
Unit 14 Freedom fighters 45
Unit 15 Destinations 58
Unit 16 The United States of America 73
Unit 17 Disabilities 88
Unit 18 Inventions 105
Unit 19 The Merchant of Venice 120
Unit 20 Archaeology 136
参考答案 151