Unit 1 Lesson 1―Lesson 2
Unit 2 Lesson 3―Lesson 4
Unit 3 Lesson 5―Lesson 6
Unit 4 lesson 7―Lesson 8
Unit 5 Lesson 9―Lesson 10
Unit 6 Lesson 11―Lesson 12
Unit 7 Lesson 13―Lesson 14
Unit 8 Lesson 15―Lesson 16
Unit 9 Lesson 17―Lesson 18
Unit 10 Lesson 19―Lesson 20
Unit 11 Lesson 21―Lesson 22
Unit 12 Lesson 23―Lesson 24
**套综合测试题Lesson 1―Lesson 24
Unit 13 Lesson 25―Lesson 26
Unit 14 Lesson 27―Lesson 28
Unit 15 Lesson 29―Lesson 30
Unit 16 Lesson 3l―Lesson 32
Unit 17 Lesson 33―Lesson 3