单项选择题
A.and quench it in oil B.cherry red and quench in water C.and let it cool slowly in the air D.and carbonize
A drilled hole is accurately finished to size with a （）...
单项选择题A drilled hole is accurately finished to size with a （）
A.center drill B.finish drill C.broach D.reamer
Which of the files listed is tapered on three sides and...
单项选择题Which of the files listed is tapered on three sides and is used to file acute internal angles?（）
A.Mill B.Round C.Square D.Triangular
Using a file without a handle may result in （）A.your wo...
单项选择题Using a file without a handle may result in （）
A.your work becoming rounded B.injury to your hand C.overheating of the file D.pinning
