1 A The Oceans 1
1 B Tide Pools 3
2 A Computer Games in Education 5
2 B How to Be a Game Programmer 7
3 A The Rock Cycle 9
3 B The Natural Wonders of Bryce Canyon 11
4 A What Is Hail? 13
4 B The Sky Is Falling! 15
5 A Food Chains 17
5 B Fungus Farmers 19
6 A The Work of an Archaeologist 21
6 B The Process of an Archaeological Dig 23
7 A Electromagnets 25
7 B Electricity's Journey 27
8 A Water Properties 29
8 B Mangrove Trees Survive the Salt 31
9 A The History of Printing 33
9 B Hieroglyphs Uncovered 35
10 A The Scientific Process 37
10 B Exploring the World 39
11 A How Animals Cope 41
11 B It's a Skunk's Life 43
12 A How the Heart Works 45
12 B Why Work Out? 47
13 A Types of Volcanoes 49
13 B Mount Rainier 51
14 A The Prairie Ecosystem 53
14 B Prairie Dog Towns 55
15 A Transportation Innovations 57
15 B Incredible Inventors 59
16 A The Mighty Insect 61
16 B The Dragonfly: Ancient One 63
17 A Mountains 65
17 B Trailblazing Volunteers 67
18 A The Life of a Tree 69
18 B Tree Rings: Diary of a Life 71
19 A What Causes Lightning? 73
19 B Lightning Safety 75
20 A Space Mysteries 77
20 B Mars, Anyone? 79
21 A The History of Vaccinations 81
21 B What You Should Know About Rabies 83
22 A Energy from the Sun 85
22 B A Solar Eclipse 87
23 A Fire and the Forest Ecosystem 89
23 B Kirtland's Warbler 91
24 A The History of Lights 93
24 B You Can Help Conserve Electricity 95
25 A What Is the Wind? 97
25 B Making a Wind Vane 99
附录 101
Answer Key 101
Reading Rate 103
Comprehension Score 104
Comprehension Skills Profile 105