例句與造句

1. Lopez admitted skipping inexpensive but critical metal-hardening heat treatments on parts made in his machine shop from 1997 to 1999.
2. Alloy 617 was at the time considered to be the easiest to fabricate as it does not require a precipitation-hardening heat treatment, while the precipitation Alloys 263 and 740 offer superior creep and corrosion resistance respectively.
3. It's difficult to find hardening heat treatment in a sentence. 用hardening heat treatment造句挺難的