英文關鍵字
alga
algae
aquatic
background
bacteria
biology
bluegreen
chemical
circulation
color
cyanobacteria
depletion
ecology
environment
flora
ganga
grass
green
ground
growth
lake
leaf
motion
natural
nature
nutrients
organic
organism
oxygen
panning
photosynthesis
plant
plantation
polluted
pollution
pond
potable
reservoir
river
slow
stagnant
still
stream
summer
surface
texture
toxic
unhealthy
view
water
yamuna