英文關鍵字
algae
biology
blooming
close
color
contaminated
danger
deficiency
detail
dirt
dirty
down
drainage
ecology
environment
environmental
feather
flora
green
lake
marsh
mud
natural
nature
ocean
organism
oxygen
pattern
plant
polluted
pollution
pond
purity
river
scum
slime
surface
swamp
water
wet
white