Unit 1 Big Bucks the Easy Way 1
Unit 2 Deer and the Energy Cycle 11
Unit 3 Why Do We Believe That the Earth Is Round? 18
Unit 4 Jim Thorpe 26
Unit 5 To Lie or Not to Lie—The Doctor's Dilemma 36
Unit 6 How to Mark a Book 44
Unit 7 The Luncheon 52
Unit 8 The New Caves 60
Unit 9 Journey West 68
Unit 10 Why People Work 76
Appendix Ⅰ：Key to Exercises(Units 1—10) 84
Appendix Ⅱ：Chinese Translations of the Texts(Units 1—10) 107