盘车手轮是在人力提升轿厢的力未超过_N时，维修人员可以用盘车手轮和制动器两个工具，人为操纵，使轿厢就近停靠，曳引机上的盘车手轮电器开关应_在_。

The _______ boy was last seen _______ near the East Lake.

A．missing; playing

B．missing; play

C．missed; played

D．missed; to play