英文關鍵字
bacteria
ban
brown
chrome
cold
color
conserve
contamination
dirty
drink
drought
ecology
environment
faucet
filter
flowing
ground
iron
metals
minerals
nondrinkable
old
outdoor
outside
pipes
pollute
pollution
potable
pressure
purification
purify
quench
running
rust
rusty
spout
stream
tap
thirst
unhealthy
wash
waste
wasting
water
well
wet