CONSERVATION
저자: Spring Loc
1. vegetation
2. nature's defence
2.1. laws
3. Circulation
3.1. rapid run-off
3.1.1. frequent flood
3.1.2. leave little dry water
3.2. hydro-electric dams
4. deforestation
4.1. disappearance
4.1.1. variety of plants and animals
4.2. destruction
4.2.1. the habitat of animals