单项选择题
Which of the listed effects represents the purpose of heat treating steel?（）
A.Develop ductility B.Improve machining qualities C.Relieves stresses D.All of the above
单项选择题 Which of the following nondestructive testing methods can be used to detect a suspected subsurface defect in a tail-shaft liner?（）
单项选择题 To anneal a copper gasket, you should heat the gasket（）
单项选择题 A drilled hole is accurately finished to size with a （）
