When you read the book, you’d better make a mark you have any questions.A. at whichB. at

When you read the book, you’d better make a mark you have any questions.
A. at which
B. at where
C. the place
D. where

A. at whichB. at whereC. the place(答案→)D. where解析： 本句最关键是要充分理解句义。句义：当你读书的时候，你最好在你有问题的地方做好标识。本句很容易会使用定语从句。但是根据句义可知缺少表示地点的先行词。故使用where引导的地点状语从句来修饰谓语动词make a mark。故D正确。

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