英文關鍵字
acid
archaeological
archaeology
background
business
chemical
clean
cleaning
coin
coins
converter
copper
corroded
currency
digger
economy
equipment
finance
financial
hand
history
hobby
liquid
metal
money
new
normal
numismatics
numismatist
ointment
patina
patination
phosphoric
prepares
protect
protective
rust
safety
saving
soda
sulfuric
their