英文關鍵字
air
biochemical
biological
black
breathing
canister
chemical
contaminate
contamination
covert
danger
disaster
environment
fear
filter
fog
fumes
gas
gasmask
germ
harmful
hazard
hazardous
hazmat
head
horror
inhale
man
mask
ominous
person
poisonous
precaution
prevention
protect
protection
respirator
safety
scary
sinister
smog
smoke
survival
terrorism
threat
toxic
ventilator
warfare