英文關鍵字
atmosphere
black
cloud
concentration
danger
dark
dense
detail
drawing
ecology
emission
environment
exhaust
from
fuel
fumes
gases
gasoline
gray
harm
hydrocarbon
incomplete
influence
iron
metal
nitrogen
outdoor
pipe
poison
poisoning
pollution
product
protector
quality
reservoir
scale
smog
soot
spot
steam
steel
substance
tire
toxic
transparent
transport
vehicle
wheel
white