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C O N T E N T S

SECTION I
1 Fahrenheit, Celsius & Kelvin ........ 6
2 Is Snow Frozen Rain? ........ 7
3 Can It Ever Be Too Cold To Snow? ........ 7
4 Electrical Current ........ 8
5 How Does an Electric Eye Work? ........ 9
6 Pollution ........ 10
7 Where Does Our Trash Go? ........ 11
8 When Was Air-Conditioning Invented? ........ 12
9 Earth, Then & Now ........ 13
10 Planet Earth ........ 14
11 How Old Is the Universe? ........ 15
12 The Solar System ........ 16
13 Is the Earth Perfectly Round? ........ 16
14 How Long Has There Been Life on Earth ........ 17
15 Natural Cycles ........ 18
16 What Are the “Bends”? ........ 19
17 Gravity ........ 20
18 How Old Is the Moon? ........ 21
19 Light & Refraction ........ 22
20 Do People Really See Mirages? ........ 23
21 Minerals ........ 24
22 Does Water Have Taste? ........ 25
23 Where Is the Wettest Place on Earth? ........ 25
24 Dating the Earth ........ 26
25 Why Is Uranium Used in Atomic Bombs? ........ 27
26 Global Warming & the Greenhouse Effect ........ 28
27 Where Is the Biggest Desert in the World? ........ 29
28 Earthquakes ........ 30
29 Major Earthquakes ........ 31
30 What Was the Greatest Earthquake in History? ........ 32
31 Protection of the Earth ........ 33
32 Do Animals Live Everywhere on Earth? ........ 34
33 Magnetism ........ 35
34 When Was the Compass Invented? ........ 36

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