英文關鍵字
alaska
bridge
cable
cloud
commercial
construction
crossing
crude
delta
energy
engineering
environment
exploration
flowing
forest
fuel
gas
gasoline
greenhouse
industrial
industry
junction
landscape
metal
metallic
mode
mountains
natural
nature
nonrenewable
north
oil
petroleum
pipeline
power
progress
resource
resources
river
sky
structure
technology
trans
transport
transportation
trees
usa