英文關鍵字
aftermath
background
bad
brown
carelessness
catastrophe
chemical
civilization
clean
damage
danger
day
dense
dirt
dirty
dump
dynamic
ecology
environment
factory
float
garbage
harm
hazard
industrial
industry
lake
layer
liquid
litter
movement
mud
nature
piece
pollute
pollution
pond
river
save
sewage
sewer
substance
surface
texture
toxic
trash
unhygienic
waste
water
wood