问题
选择题
He asked Mary whether she had passed the exam ________．
A．yesterday
B．the day before
C．the day ago
D．before the day
答案
答案：B
考查时态，yesterday和一般过去时连用；before用在完成时态中，但是“前天”应表达成the day before (yesterday)。句意：前天他问玛丽是否考试过关了。