船长40米以上的J级航段的自航船可不必设置双层底。
参考答案:错
–I’m very disappointed in my next-door neighbour.
--______?
--He promised not to make noises at midnight, but he’s still doing so.
A.What’s wrong with you
B.How come
C.I beg your pardon
D.Can I help you
润滑系统包括()、集滤器,机油粗、细滤清器、散热器、润滑油道以及机油压力表和传感器等辅助器件。
A、油底壳
B、机油泵
C、限压阀
D、机油管