问题补充:
—Where did you pick up the stamp?
—It was at the post office we worked in the summer vacation.
A. that
B. where
C. which
D. when
答案:
A. that
(答案→)B. where
C. which
D. when
解析:B 考察定语从句和强调句型。Where引导定语从句 ,在从句做地点状语,修饰先行词the post office,这是强调句的省略形式,句子补充完整是It was at the past office where we worked in the summer vacation that I picked up the stamp。强调的是整个定语从句部分。