Unit 1 How do you study for a test?Verb+by+v-ing（动词＋by＋动词-ing） 1
Unit 2 Iused to be afraid of the dark.Used to（used to的用法） 5
Unit 3 Teenagers should be allowed to choose their own clothes.Passive voice with should（含should的被动语态） 9
Unit 4 What would you do?Second conditional Would for advice（would构成的虚拟条件句） 15
Unit 5 It must belong to Carla.Modals for making inferences（表示推测的情态动词） 19
Unit 6 I like music that I can dance to.Attributive clauses（定语从句） 23
Unit 7 Where would you like to visit?Would and hope to for expressing desires（would和hope to表达意愿） 29
Unit 8 I'll help clean up the city parks.Phrasal verbs（短语动词） 33
Unit 9 When was it invented?The passive voice（被动语态） 39
Unit 10 By the time I got outside,the bus had already left.Past perfect（过去完成时） 45
Unit 11 Could you please tell me where the restrooms are?Indirect questions（间接疑问句） 51
Unit 12 You're supposed to shake hands.Be supposed to(be supposed to) 57
Unit 13 Rainy days make me sad.Make+sb+infinitive/adjective（make＋某人＋不定式／形容词） 61
Unit 14 Have you packed yet?Present perfect with already and yet（含already和yet的现在完成时） 65
Unit 15 We're trying to save the manatees!Tense of verbs（动词时态） 69
AppendixAppendix 1 Nouns（名词） 81
Appendix 2 Pronouns（代词） 89
Appendix 3 Articles（冠词） 99
Appendix 4 Prepositions（介词） 107
Appendix 5 The comparative and superlatives degrees of adjectives and adverbs（形容词和副词的比较级和最高级） 115
Appendix 6 Conjunctions（连词） 123
Appendix 7 The numerals（数词） 131
Appendix 8 Nonfinite verbs（非谓语动词） 139
Appendix 9 Subject-predicate agreement（主谓一致） 147
Appendix 10 Sentence types（句子种类） 155
Appendix 11 Word formation（构词法） 167
Appendix 12 Adverbial clause（状语从句） 177