英文關鍵字
air
background
boy
building
catastrophe
chemical
chimneys
china
choke
climate
cough
damage
danger
dirty
disaster
ecological
ecology
energy
environment
face
factory
gas
gasp
global
guy
hazard
health
human
illness
industrial
industry
infection
kid
male
man
mask
one
outdoors
people
person
pipes
poisonous
pollution
problem
protect
protection
respirator
smoke
stack
young