磨床液压系统中，工作台停留时间的长短，主要与（）有关。

A.换向阀

B.停留阀

C.节流阀

D.溢流阀

All entries in the official logbook must be signed by the master and（）.

A.the union representative

B.the person aboat whom the entry concerns

C.no one else

D.one other crew member