Lesson 1 1
Lesson 2 18
Lesson 3 31
Lesson 4 46
Lesson 5 60
Lesson 6 78
Lesson 7 95
Lesson 8 109
Lesson 9、10 120
Lesson 11 134
Lesson 12 150
Lesson 13、14 170
Lesson 15 192
Lesson 16、17 203
附录一 Key to exercises 215
附录二 Useful phrases and expressions 243