CONTENTS 1
Lesson One 1
Text:Gravity 1
Grammar：Ⅰ．句子的种类 4
Ⅱ．状语从句（一） 6
Reading Material:Gravity and Spaceships 17
Lesson Two 20
Text:The Sun,the Moon and the Stars 20
Grammar：Ⅰ．形容词和副词的级 25
Ⅱ．状语从句（二） 28
Reading Material:Evaporation 34
Lesson Three 37
Text:Science and Facts 37
Grammar：主语从句，表语从句，宾语从句，同位语从句 43
Reading Material,Magnets 51
Lesson Four 54
Text:A Common Eiement 54
Grammar：What引导的从句 60
Reading Material:Air Pressure 65
Text:Light 68
Lesson Five 68
Grammar：定语从句（一） 73
Reading Material:Atoms 83
Lesson Six 86
Text:Cloud,Fog and Dew 86
Grammar：定语从句（二） 92
Reading Material:How Heat Travels 98
Lesson Seven 101
Text:A Story About Edison 101
Reading Material:Different Forms of Water 115
Grammar：复习 115
Lesson Eight 118
Text:Radar for Peaceful Purposes 118
Grammar：不定式（一） 124
Reading Material:Watson-Watt and Radar 132
Lesson Nine 135
Text:Li Shi-zhen 135
Grammar：不定式（二） 140
Reading Material:When and How to Collect Herbe 148
Text:Sound Has Speed 151
Lesson Ten 151
Grammar：动名词 158
Reading Material:Iron Smelting 164
Lesson Eleven 167
Text:Computers 167
Grammar：分词（一） 174
Reading Material:Chemical Reaetion in a Living Body 181
Lesson Twelve 184
Text:Fire 184
Grammar：分词（二） 192
Reading Material:Electric Current 198
Lesson Thirteen 201
Text:Science and Scientific Research 201
Grammar：复习 213
Reading Material:Molecules 213
Lesson Fourteen 216
Text:Electron and Atom 216
Grammar：虚拟语气 221
Reading Material:How to Put Out a Fire 232
Text:Something About Electrification 236
Lesson Fifteen 236
Grammar：It用法小结 241
Reading Material:How to Build a Fire 249
Lesson Sixteen 252
Text:Expansion and Contraction 252
Grammar：As用法小结 259
Reading Material:Four Zones of the Earth 269
Lesson Seventeen 272
Text:Supersonic Planes 272
Reading Material:Fission and Fusion 286
Grammar：复习 286
Supplementary Readings 290
Ⅰ．Water in the Air 290
Ⅱ．What Are Magnets? 294
Ⅲ．Can People Really Make Rain? 297
Ⅳ．Force,Work,Energy and Power 300
Ⅴ．How Changes Are Brought About? 303
Ⅵ．Water Resources 309
复习测验题Review Test 319
“Word Study”索引 338
总词汇表 342