请看下面的题目，where 是引导什么从句？
When you read the book, you’d better make a mark _________ you have any questions.
A. at which B. at where C. the place where D. where
【分析】此题正确答案选D，where 在此意为“在……的地方”，用以引导地点状语从句，全句意为“当你读这本书时，你最好在有问题的地方作一个记号”。但是有的同学却根据试题所提供的选项想当然认为这是一道考查定语从句关系词的选择与辨析的试题，于是在A、B、C三项中绞尽脑汁，当然最终不可能得出正确答案。请做以下试题，看看是考查定语从句还是状语从句：
(1) She found her wallet _________ she lost it.
A. where B. when C. in which D. that
答案选A，where 意为“在……的地方”，引导地点状语从句。
(2) The school was built _________ there had once been a church.
A. where B. when C. in which D. that
答案选A，where 意为“在……的地方”，引导地点状语从句。
(3) You should let your children play _________ you can see them.
A. where B. when C. in which D. that
答案选A，where 意为“在……的地方”，引导地点状语从句。
(4) Now he works in the factory _________ his father used to work.
A. where B. when C. in which D. that
答案选A，where引导定语从句，表示地点。
(5) You should make it a rule to leave things _________ you can find them again.
A. when B. where C. then D. there
答案选B，where 意为“在……的地方”，引导地点状语从句。
(6) After living in Paris for fifty years, he returned to the small town _________ he grew up as a child.
A. where B. when C. in which D. that
答案选A，where引导定语从句，表示地点。
比较以下两句，含义大致相同，但where 的用法不同：
We’ll go where working conditions are difficult.
我们要去工作条件艰苦的地方。（状语从句）
We’ll go to the place where working conditions are difficult.
我们要去工作条件艰苦的地方。（定语从句）