Lesson 1 1
Lesson 2 1
Lesson 3 2
Unit 1 2
Lesson 5 3
Lesson 6 3
Lesson 7 4
Unit 2 4
Lesson 9 5
Lesson 10 5
Lesson 11 6
Unit 3 7
Lesson 13 7
Lesson 14 8
Lesson 15 9
Unit 4 10
Lesson 17 11
Lesson 18 11
Lesson 19 12
Unit 5 13
Lesson 21 14
Lesson 22 14
Lesson 23 15
Unit 6 16
期中练习（Unit 7） 17
Lesson 29 19
Lesson 30 20
Lesson 31 21
Unit 8 21
Lesson 33 22
Lesson 34 23
Lesson 35 23
Unit 9 24
Lesson 37 25
Lesson 38 25
Lesson 39 26
Unit 10 27
Lesson 41 27
Lesson 42 28
Lesson 43 29
Unit 11 29
Lesson 45 30
Lesson 46 31
Lesson 47 31
Unit 12 32
Lesson 49 33
Lesson 50 33
Lesson 51 34
Unit 13 35
期末练习（Unit 14） 36
Lesson 57 39
Lesson 58 40
Lesson 59 40
Unit 15 41
Lesson 61 42
Lesson 62 42
Lesson 63 43
Unit 16 43
Lesson 65 44
Lesson 66 44
Lesson 67 45
Unit 17 46
Lesson 69 46
Lesson 70 47
Lesson 71 47
Unit 18 48
Lesson 73 48
Lesson 74 49
Lesson 75 49
期中练习（Unit 19） 50
Lesson 77 52
Lesson 78 53
Lesson 79 53
Unit 20 54
Lesson 81 54
Lesson 82 55
Lesson 83 55
Unit 21 56
Lesson 85 56
Lesson 86 57
Lesson 87 57
Unit 22 58
Lesson 89 58
Lesson 90 59
Lesson 91 59
Unit 23 59
期末练习（Unit 24） 60
参考答案 65