Unit 1 1
Unit 2 6
Unit 3 10
Unit 4 15
Revision Exercises 19
Key to Revision Exercises 27
Unit 5 31
Unit 6 37
Unit 7 41
Unit 8 46
Revision Exercises 50
Key to Revision Exercises 58
Unit 9 62
Unit 10 67
Unit 11 71
Unit 12 77
Revision Exercises 81
Key to Revision Exercises 89
Unit 13 93
Unit 14 98
Key to Exercises （Unit 1—Unit 14） 103
Key to Revision Exercises （Unit 1—Unit 14） 116
Key to Supplemantary Reading Exercises 121
课文参考译文 122
补充阅读参考译文 134