英文關鍵字
blue
business
carriage
city
clouds
commerce
concrete
construction
container
crane
danger
day
disaster
dock
energy
engineering
environment
equipment
fast
green
heavy
industrial
industry
lines
machine
metal
moving
old
pan
poles
port
power
russia
rusty
safety
sky
speed
station
steel
summer
symbol
technology
train
transportation
tree
water
white
wires
work
zone