英文關鍵字
attraction
broken
business
chips
clear
crane
crushed
damaged
dirty
disposal
dump
ecology
education
electric
electromagnets
environment
experiment
factory
ferrous
filings
force
garbage
horseshoe
industrial
industry
iron
junk
junkyard
magnet
magnetic
material
metal
nobody
old
outdoors
pile
pollution
recycle
recycling
reuse
rust
science
scrap
scratches
sky
stack
steel
technology
waste
yard