英文關鍵字
accord
air
biosphere
burning
cleaning
cleanup
color
communications
conservation
contains
day
dimensional
disaster
earth
environmental
fire
global
hand
heat
human
illness
international
kyoto
male
medium
natural
nature
oil
people
planet
pollution
real
reforestation
reserves
shape
shot
slick
sphere
symbol
technology
three
time
toxic
warming
waste
water