—How often do you eat out? 

—_____, but usually once a week.

A．Just hang on second

B．It depends

C．Come off it

D．Generally speaking

喷熔前，清洁零件表面，除去油污、锈斑外，还应进行（），以保证喷熔质量。

A.凹切

B.粗化

C.活化

D.预热