英文關鍵字
3d
alert
animation
attention
background
beware
black
board
building
caution
construction
danger
dangerous
element
exclamation
halt
hazard
icon
industrial
industry
information
interface
isolated
isometric
mark
message
motion
pressure
risk
road
safety
secure
security
shadow
shape
sign
street
style
symbol
threat
triangle
warn
warning
white
work
yellow