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單項選擇題

To anneal a copper gasket, you should heat the gasket（）

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

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單項選擇題

A drilled hole is accurately finished to size with a （）

A.center drill
B.finish drill
C.broach
D.reamer

單項選擇題

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