英文關鍵字
abstract
agriculture
algae
bridge
bright
build
cement
clean
construction
dam
ecology
fence
flow
fresh
grass
grate
green
greenhouse
industrial
industry
jet
light
metal
mountain
nature
old
plant
production
rapid
rays
reliability
resources
river
safety
scaffolding
sky
steel
stones
stream
structure
sun
technology
texture
tree
trickle
water
wood