把钩工在串车进出车场时，应目接目送串车，并与信号工配合默契，以便做好随时发出停车信号的准备。
参考答案：对
Whenever he was asked why he was late for class，he would answer carelessly，______ the same thing.
A．saying
B．said
C．to say
D．say
速效、短效的镇痛药是（）
A.美沙酮
B.吗啡
C.哌替啶
D.曲马朵
E.芬太尼
