问题
选择题
I was on the highway _______ this car went past followed by a police car. They ______ at least 150 kilometers an hour.
A.when; should have been driving
B.while; would have driven
C.as; could have driven
D.when; must have been driving
答案
答案:D
考查连词和情态动词用法。因为go past(经过)是短暂性动词所以不能与while连用,while只能和延续性动词连用。When既可以与短暂性动词也可以与延续性动词连用。第二空表示对过去某时正在发生情况的肯定推测。句意:当一辆汽车从我旁边经过,后面跟着一辆警车的时候,我正在高速公路上。他们当时的速度至少150公里每小时。