“AC arc welding”造句，怎麼用AC arc welding造句

Usage and maintenance of welding and cutting machine(4)-- Installation,usage and maintenance for AC arc welding machine

Usage and maintenance of welding and cutting machines(5)--Repairing examples and refitting for AC arc welding machines

A energy-saving anti-electric shock AC arc welding mach- ine replaced SCR by contractor in energy-saving switch is advanced.