Unit 11 Scientific achievement 1
Unit 12 Fact and fantasy 15
Unit 13 The water planet 29
Unit 14 Freedom fighters 40
Unit 15 Destinations 54
Unit 16 The United States of America 69
Unit 17 Disabilities 84
Unit 18 Inventions 97
Unit 19 The Merchant of Venice 114
Unit 20 Archaeology 133
参考答案 149