- 作 者：郑书皓编
- 出 版 社：上海：上海远东出版社；牛津大学出版社
- 出版年份：1999
- ISBN：7806138692
- 标注页数：257 页
- PDF页数：267 页
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Unit 7 Living Things and AirCommon gases 2
Composition of the air 6
What is air? 10
Uses of the gases in air 10
Breathed and unbreathed air 11
What makes these differences? 14
Respiration 15
How air passes in and out of us 17
Breathing in and out 19
Different breathing systems 23
Do plants respire? 24
How do plants obtain energy? 27
Most plants contain starch 28
Photosynthesis 31
Oxygen/carbon dioxide balance 33
Photosynthesis and food chains 34
Food webs 34
The pollution of our air 36
Summary 37
Difficult words 40
Unit 8 ElectricityUse of electricity 42
Conductors,insulators 48
Electric current 49
Resistance 50
Lighting and heating effects 53
Fuses and circuit breakers 58
Electricity at home 59
Magnetism 72
Electromagnets 77
Electrochemistry 82
Summary 85
Difficult words 87
Unit 9 Heat TransferHeat energy 92
Heat transfer in gases 93
Convection in liquids 96
Heat transfer in solids 99
Conduction in air and water 101
Radiation 103
Applications of heat transfer 108
How living creatures keep warm 112
Summary 115
Difficult words 117
Unit 10 Hydrogen,Acids and AlkalisProperties of hydrogen 120
Some uses of hydrogen 122
Breaking down water 123
Metals and water 126
Reactivity 134
Metals and acids 135
Reacting with sulphuric acid 137
Comparing reaction rates 138
Reactivity series 140
Acids and alkalis 141
The pH scale 145
Acid+Alkali=? 147
Neutralization and concentration 150
Applications of neutralization 154
Summary 156
Difficult words 159
Unit 11 Detecting the environmentOur senses and sense organs 162
Light and eyes 164
How a pinhole camera works 166
Thick lens and thin lens 172
Making sharp images 174
How our eyes see objects 174
How cameras 'see' objects 175
Comparing the eye with the camera 176
Normal eye,long and short sight 176
Limitations of vision 180
The noisy world 183
Pitch 188
Transmission of sound 191
The range of hearing 197
Taste and smell 198
The sense of smell 203
Skin 207
Into the brain 209
Persistence of vision 212
Summary 214
Difficult words 217
Unit 12 Forces and MovementWhat is force? 220
Friction 226
Weighing 231
Levers 235
Using levers 237
Human lever systems 239
Work and energy 242
Pulleys 245
Action and reaction 247
Summary 251
Difficult words 254
Index 255