【判断题】过滤操作的推动力是滤渣和过滤介质两侧的压力差。
【单选题】At the sight of the policeman, ____ from behind the door.
B.
the boy was rushing out
D.
rushing out was the boy
【单选题】The audience waited until the curtain rose and then ____ laughter at the sight of the funny actor. [ ]
【单选题】The audience waited until the curtain rose and then______laughter at the sight of the funny actor.