英文關鍵字
hatch
flop
steam
protection
water
manhole
street
hot
city
main
vapor
hole
smoke
urban
metal
technology
sewer
damage
emergency
iron
central
energy
heat
construction
circle
stop
zone
tape
red
security
caliduct
caution
warning
barrier
hazard
danger
safety
striped
restricted
restriction
attention
protect
dangerous
secured
system
chamber
loss
inspection
line
control
well
outdoor
transportation
round
supply
pit