问题补充:
This is the office my parents are visiting now.
A. which
B. what
C. who
D. where
答案:
(答案→)A. which
B. what
C. who
D. where
解析:考查定语从句。本题定语从句的先行词是the office,which知道先行词在句中做visit的宾语。What不是定语从句的关系词,who所指代的先行词是人;where在定语从句中做状语。句意:这就是我的父母正在参观的办公室。故A正确。