主油缸乱换向由以下那些阀引起:()。
A.退活塞阀
B.泄油阀
C.螺纹插装阀
D.主阀块上的梭阀
参考答案:B, C
It is the youngest brother rather than his two elder brothers ______ been fined for
breaking the traffic rules. [ ]
A. whom have
B. who have
C. that have
D. that has
根据我国的有关规范[JTS165-5-2009],关于液化天然气船舶的进出港航道的使用,以下说法哪个正确()。
A、在实行交通管制的条件先,液化天然气船舶可与其他船舶共用
B、在护航条件下,液化天然气船舶可与其他船舶共用
C、在能见度良好条件下,可与其他船舶共用
D、必须实行液化天然气船舶单向通航