1 A Using Energy to Ride a Bike 1
1 B Fixing a Flat 3
2 A Animals of the Forests 5
2 B A Listening Walk in the Forest 7
3 A The Constellations 9
3 B A Visit to a Planetarium 11
4 A The Need for Plants 13
4 B Grow Your Own Vegetables 15
5 A What Is a Veterinarian? 17
5 B Are Dogs Getting Healthier? 19
6 A The Features of Earth's Surface 21
6 B Down the Mississippi River 23
7 A Simple Machines 25
7 B A Simple Solution 27
8 A The Scientific Discoveries of Benjamin Franklin 29
8 B How Do Kites Fly? 31
9 A The Truth About Sharks 33
9 B The Crittercam 35
10 A Types of Clouds 37
10 B Meteorologists Predict the Weather 39
11 A Fruits and Vegetables:A Key to Good Health 41
11 B Exotic Fruits 43
12 A Crossing the Land with Steam Power 45
12 B Robert Fulton and the Steamboat 47
13 A Seasons Around the World 49
13 B Staying Warm in Winter 51
14 A What Is a Mammal? 53
14 B Mammals with Pouches 55
15 A How to Organize a Great Science Fair Project 57
15 B A Tasteful Science Experiment 59
16 A Rocks and Minerals 61
16 B The Hope Diamond 63
17 A Water Is Needed for Life 65
17 B How Cacti Survive with Little Water 67
18 A Flowering and Nonflowering Plants 69
18 B The Honeybee and Pollination 71
19 A Waste and Recycling 73
19 B Our Class Recycling Project 75
20 A Elijah McCoy,Inventor 77
20 B Why Do We Say That? 79
21 A The Push and Pull of Magnets 81
21 B Making Magnets 83
22 A The Senses 85
22 B A Fish Out of Water 87
23 A Telescopes and Microscopes 89
23 B An Important Scientist 91
24 A The Life Cycle of a Tree 93
24 B Growing Applesauce 95
25 A How Animals Defend Themselves 97
25 B Animals Keeping Clean 99
附录 101
Answer Key 101
Reading Rate 103
Comprehension Score 104
Comprehension Skills Profile 105