英文關鍵字
chemical
chemistry
cleanup
cruel
danger
dirt
dirty
dump
dumping
ecology
environment
exterior
filthy
foam
garbage
health
horror
impure
junk
lake
material
natural
nature
ocean
oil
organism
poisonous
polluted
pollution
poor
poverty
problem
reserve
river
rotting
rubbish
sea
sewage
smell
smelling
stream
substance
summer
toxic
trash
ugliness
unhealthy
unhygienic
unpleasant
waste
water
waves
wildlife