Lesson 1 1
Lesson 2 1
Lesson 3 2
Unit 1 2
Lesson 5 3
Lesson 6 4
Lesson 7 5
Unit 2 6
Lesson 9 7
Lesson 10 7
Lesson 11 8
Unit 3 9
Lesson 13 10
Lesson 14 11
Lesson 15 12
Unit 4 13
Lesson 17 14
Lesson 18 14
Lesson 19 15
Unit 5 16
Lesson 21 17
Lesson 22 18
Lesson 23 19
Unit 6 20
期中练习（Unit 7） 21
Lesson 29 24
Lesson 30 24
Lesson 31 25
Unit 8 26
Lesson 33 26
Lesson 34 27
Lesson 35 28
Unit 9 29
Lesson 37 30
Lesson 38 30
Lesson 39 31
Unit 10 32
Lesson 41 33
Lesson 42 33
Lesson 43 34
Unit 11 35
Lesson 45 36
Lesson 46 36
Lesson 47 37
Unit 12 38
Lesson 49 38
Lesson 50 39
Lesson 51 39
Unit 13 41
期末练习（Unit 14） 41
Lesson 57 45
Lesson 58 46
Unit 15 47
Lesson 59 47
Lesson 61 48
Lesson 62 49
Lesson 63 49
Unit 16 50
Lesson65 51
Lesson66 51
Lesson67 52
Unit 17 52
Lesson69 53
Lesson70 53
Unit 18 54
Lesson71 54
Lesson73 55
Lesson74 56
Lesson75 56
期中练习（Unit 19） 57
Lesson 77 60
Lesson78 60
Lesson79 61
Unit 20 61
Lesson81 62
Lesson82 62
Unit 21 63
Lesson83 63
Lesson85 64
Lesson86 64
Lesson87 65
Unit 22 65
Lesson89 65
Lesson90 66
Lesson91 66
Unit 23 67
期末练习（Unit 24） 67
参考答案 73