When he was asked about the question where he was last night, he was ______.     [ ]

A. at loss  

B. in a loss  

C. at a loss  

D. with losses

Starting motors，generators，and other spark producing devices should be mounted as high above the bilges as possible to（）.

A.keep them dry when the bilges are full of water

B.keep them cool when the vessel is underway

C.make them more accessible for repairs

D.prevent accidental ignition of any gasoline vapors that may have accumulated in the bilges