He waited until the volcano became quiet.He waited___quiet.(选择题)
问题描述：
He waited until the volcano became quiet.He waited___quiet.(选择题)
a)to the volcano to become
b)the volcano to become
c)the volcano became
d)for the volcanoto became
答
a
wait做及物动词时要＋for.做不及物动词时,选项为谓语动词wait的补语,所以排除b和c .
又,若选d则应是become而非过去式,所以选a,to在这里的意思同till.