機器
air
atmosphere
big
black
business
capacity
car
career
cargo
combustion
construction
dirty
drive
dump
ecology
energy
environment
equipment
exhaust
fuel
gas
gasoline
gold
gray
health
huge
industrial
industry
iron
large
load
machinery
metal
outdoors
pipe
poison
polluted
pollution
production
road
smog
technology
toxic
transport
transportation
truck
vehicle
white
work