Unit 1 1Background Information 1Language Points 1Chinese Version of Text A 7Key to the Exercises 8Unit 2 12Background Information 12Language Points 12Chinese Version of Text A 16Key to the Exercises 17Unit 3 21Background Information 21Language Points 21Chinese Version of Text A 24Key to the Exercises 25Unit 4 29Background Information 29Language Points 29Chinese Version of Text A 34Key to the Exercises 35Unit 5 38Background Information 38Language Points 38Chinese Version of Text A 45Key to the Exercises 46Unit 6 49Background Information 49Language Points 49Chinese Version of Text A 54Key to the Exercises 56Unit 7 59Background Information 59Language Points 59Chinese Version of Text A 64Key to the Exercises 65Unit 8 69Background Information 69Language Points 69Chinese Version of Text A 74Key to the Exercises 75Unit 9 79Background Information 79Language Points 79Chinese Version of Text A 83Key to the Exercises 85Unit 10 88Background Information 88Language Points 88Chinese Version of Text A 94Key to the Exercises 96Key to the Text 99