Unit 1 What Is the Environment? 1
1-1 What Is the Environment? 2
1-2 The Living and Non-living Environment 4
1-3 The Natural and Man-made Environment 5
1-4 Human Influence on Nature 7
Unit 2 Recycling 10
2-1 What Is Recycling? 11
2-2 How Can We Recycle? 13
2-3 What Is Rubbish? 15
2-4 5Rs 18
Unit 3 Saving Energy 22
3-1 Humans Cannot Live without Energy 24
3-2 What Is Energy? 26
3-3 Energy and the Environment 30
3-4 Solutions for a Sustainable Future 32
3-5 Energy-efficient Labels 35
Unit 4 We Want Cleaner Air! 38
4-1 All Living Things Need Air to Live 39
4-2 Air Pollution 41
4-3 Indoor Health 44
Unit 5 Biodiversity 47
5-1 What Is Biodiversity? 48
5-2 Why Is Biodiversity Important? 52
5-3 Why Are We Losing Biodiversity? 53
5-4 How Can We Protect Biod iversity? 55
Unit 6 Music or Noise? 58
6-1 What Is Noise? 59
6-2 Major Noise Sources 60
6-3 Health Effects of Noise 60
6-4 Noise Measurement 61
6-5 Noise Control 65
Unit 7 Water and You 68
7-1 Water Is Vital to All Life 70
7-2 Where Does Our Household Water Come from and Go to? 72
7-3 Is Water Abundant or Scarce? 74
7-4 Water Pollution 77
7-5 Water Conservation 78