Question

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．a(chǎn)s; could have driven

D．when; must have been driving

Answer 1

D

考查連詞和情態(tài)動(dòng)詞用法。因?yàn)間o past（經(jīng)過(guò)）是短暫性動(dòng)詞所以不能與while連用，while只能和延續(xù)性動(dòng)詞連用。When既可以與短暫性動(dòng)詞也可以與延續(xù)性動(dòng)詞連用。第二空表示對(duì)過(guò)去某時(shí)正在發(fā)生情況的肯定推測(cè)。句意：當(dāng)一輛汽車(chē)從我旁邊經(jīng)過(guò)，后面跟著一輛警車(chē)的時(shí)候，我正在高速公路上。他們當(dāng)時(shí)的速度至少150公里每小時(shí)。