柴油机常见的曲轴结构形式为()。
A.整体式、组合式
B.底座式、隧道式
C.整体式、分开式
D.悬挂式样、底座式
参考答案:A
Many teens don't get enough sleep because they have too much homework to do, which ________ them up at night.
A.makes
B.breaks
C.turns
D.keeps
失控船存在于()。
A、锚泊中
B、搁浅中
C、在航中
D、以上都可能