—__________?     

—Quite well, thanks.[ ]

A. What do you do?  

B. What do you think of it?

C. How are you getting on with your math ?

D. Are you quite good at English?

一般情况下，油封配合间隙保持在（）范围。

A.1.0-1.2mm

B.0.2-0.4mm

C.0.6-0.8mm

D.0.7-0.9mm