Unit 1 Unsolved Mystery——THE SEA 1
Unit 2 Winter Comes to the Animal World 10
Unit 3 LOST OVER THE ATLANTIC 19
Unit 4 The Stars of the Magi 28
Unit 5 BURIED TREASURE 37
Unit 6 LADY of the Wasteland 47
Unit 7 EIGHTEENTH CENTURY STYLE 57
Unit 8 THE GIANTS OF EASTER ISLAND 67
Unit 9 Michigan's Marching Dunes 77
Unit 10 V-DAY IN THE POLIO WAR 87
Unit 11 Sputtering African Fuse 97
Unit 12 TWO FOR A NICKEL 107
Unit 13 The"UPSTART CROW" 118
Unit 14 THE REAL SHERLOCK HOLMES 128
Unit 15 Is Your Judgment Warped? 138
Unit 16 The Truth about Those"INVISIBLE"Ads 148
Unit 17 Edward R.Murrow Reports on Britain Under Bombs 158
Unit 18 IS a Race of Robots Possible? 169
Unit 19 The War Against Hunger 179
Unit 20 Come Aboard an Atomic Sub! 189
Unit 21 Superstitious?Here's Why! 200
Unit 22 The Cloak-and-Dagger Struggle to Keep New Cars Secret 209
Unit 23 Jerry Potts,Scout Supreme 219
Unit 24 Danger by Candlelight 229
Unit 25 STRANGE MONEY 240
Unit 26 THE GREAT CHICAGO FIRE 251
Unit 27 1066 AD——THE NORMAN CONQUEST 263
Unit 28 WHO KNOWS? 274
Unit 29 THE BEGINNING OF THE HEALING ART 285
Unit 30 WHAT'S SO FUNNY? 297
Answer Key（另附） 309