Unit 11 Scientific achievement 1
Unit 12 Fact and fantasy 14
Unit 13 The water planet 27
Unit 14 Freedom fighters 37
Unit 15 Destinations 50
Unit 16 The United States of America 65
Unit 17 Disabilities 79
Unit 18 Inventions 92
Unit 19 The Merchant of Venice 109
Unit 20 Archaeology 128
参考答案 145