英文關鍵字
activities
alien
area
attention
away
background
barrier
caution
clouds
conspiracy
danger
dangerous
dead
electric
end
experiments
extraterrestrial
fence
fiction
hazard
keep
lightnings
metal
military
out
prohibited
restricted
restriction
risk
scene
sci
science
security
sign
signboard
storm
symbol
thunderstorm
trespassing
ufo
unauthorized
warning
zone