Chapter 1
CROP PRODUCTION AND MANAGEMENT 1
Chapter 2
MICROORGANISMS : FRIEND AND FOE 17
Chapter 3
SYNTHETIC FIBRES AND PLASTICS 32
Chapter 4
MATERIALS : METALS AND NON-METALS 44
Chapter 5
COAL AND PETROLEUM 56
Chapter 6
COMBUSTION AND FLAME 64
Chapter 7
CONSERVATION OF PLANTS AND ANIMALS 77
Chapter 8
CELL — STRUCTURE AND FUNCTIONS 90
Chapter 9
REPRODUCTION IN ANIMALS 100
Chapter 10
REACHING THE AGE OF ADOLESCENCE 113
Chapter 11
FORCE AND PRESSURE 127
Chapter 12
FRICTION 146
Chapter 13
SOUND 157
Chapter 14
CHEMICAL EFFECTS OF ELECTRIC CURRENT 172
Chapter 15
SOME NATURAL PHENOMENA 184
Chapter 16
LIGHT 199
Chapter 17
STARS AND THE SOLAR SYSTEM 215
Chapter 18
POLLUTION OF AIR AND WATER 239
