Unit 1
Lesson 1 Death in the Tunnel
Lesson 2 A Graveyard Mystery
Lesson 3 The Money Pit
Lesson 4 The Man——Eaters of Tsavo
Lesson 5 The Evil Eye
Lesson 6 The Rainmaker
Unit Summarizing 1
Unit 2
Lesson 7 What Happened to Amy?
Lesson 8 Mysterious Circles
Lesson 9 Cuban Stowaway
Lesson 10 A Living Fossil
Lesson 11 The 29，000-Foot Plunge
Unit Summarizing 2
Unit 3
Lesson 12 A Guardian Angel?
Lesson 13 A Shocking Experience
Lesson 14 Crocker Land：An Arctic Mirage
Lesson 15 Fish Killer
Lesson 16 The Case of the Missing Pilot
Unit Summarizing 3
Appendix
Answer Key
