WATER
作者:Libin Wan
1. states of water
1.1. solid(ice)
1.2. liquid(water)
1.3. gas(steam)
2. uses of water
2.1. drinking
2.2. cleaning
2.3. cooking
2.4. watering
3. sources of water
3.1. rivers
3.2. lakes
3.3. oceans
3.4. rain
4. water cycle
4.1. evaporation
4.2. condensation
4.3. precipitation
4.4. collection
5. properties of water
5.1. wet
5.2. clear
5.3. no taste
5.4. no smell