每班必须检查截割头（）完好情况，发现短缺或缺含金钢头的必须立即更换。

A.截齿

B.齿轮

C.伸缩筒

D.润滑油

Gasoling fumes tend to（）.

A.settle near the bottom of the blige

B.settle near the top of the bilge

C.settle evenly throughout all levels of the bilge by mixing with air

D.disperse to atmosphere