Unit One The Colorful Language Part One: Objective of the Unit（单元学习目标） Part Two: Text Exercises Part Three: Grammar Revision: Adverbial Clauses （状语从句） Part Four: Exercises for PRETCO Unit Two Customs of Communication Part One: Objective of the Unit（单元学习目标） Part Two: Text Exercises Part Three: Grammar Revision: Attributive Clause（定语从句）（1） Part Four: Exercises for PRETCO Unit Three Food Culture Part One: Objective of the Unit（单元学习目标） Part Two: Text Exercises（单元练习） Part Three: Grammar Revision: Attributive Clause（定语从句）（2） Part Four: Exercises for PRETCO Unit Four Questions of Intelligence Part One: Objective of the Unit（单元学习目标） Part Two: Text Exercises Part Three: Grammar Revision: Participle （分词）（1） Part Four: Exercises for PRETCO Unit Five Dreams of Life Part One: Objective of the Unit（单元学习目标） Part Two: Text Exercises Part Three: Grammar Revision: Participle （分词）（2） Part Four: Exercises for PRETCO Unit Six Famous People Part One: Objective of the Unit（单元学习目标） Part Two: Text Exercises Part Three: Grammar Revision: Gerund（动名词）（1） Part Four: Exercises for PRETCO Unit Seven Average but Respectable Persons Part One: Objective of the Unit（单元学习目标） Part Two: Text Exercises Part Three: Grammar Revision: Gerund（动名词）（2） Part Four: Exercises for PRETCO Unit Eight Weather and Climate Part One: Objective of the Unit（单元学习目标） Part Two: Text Exercises Part Three: Grammar Revision: Infinitive （不定式）（1） Part Four: Exercises for PRETCO Unit Nine Problems of Education Part One: Objective of the Unit（单元学习目标） Part Two: Text Exercises Part Three: Grammar Revision: Infinitive （不定式）（2） Part Four: Exercises for PRETCO Unit Ten Thanksgiving and Easter Part One: Objective of the Unlt（单元学习目标） Part Two: Text Exercises Part Three: Grammar Revision: Infinitive （不定式）（3） Part Four: Exercises for PRETCO Answers
