Question

you had better make a mark 填什么you have questions

You had batter make a mark _____ you have any question.
A which B that C when D where
请问下C和D两个选项应选哪个为什么不能选C

Answer 1

1定语从句（Attributive Clauses）在句中做定语,修饰一个名词或代词,被修饰的名词,词组或代词即先行词.
2定语从句通常出现在先行词之后,由关系词（关系代词或关系副词）引出.
3题目所考查的考点便是where=in/ at/ on/ ... which (介词同先行词搭配)
You'd better make a mark where you have any questions.
=You'd better make a mark on which you have any questions.