英文關鍵字
air
boy
building
catastrophe
chemical
chimneys
china
choke
concept
cough
damage
danger
dirty
disaster
ecological
ecology
environment
environmental
epidemic
equipment
factory
gas
gasp
global
guy
hazard
health
human
industrial
industry
kid
male
man
mask
mouth
outdoors
person
pipes
pollutant
pollution
protect
protection
respirator
sick
smoke
smokestack
urban
warming
wear
young