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

问题描述:

When you read the book,you’d better make a mark _____ you have any questions.
答案是where 我想说如果非要用which 要怎么写呢?还是不能用which?另外是不是用where了,介词就不需要了吗?

where = at which因为这个mark是在question上的,所以要多一个at,而用了从句以后,which的前面也需要保留这个at.You'd better make a mark at which you have any questions.如果去掉从句跟修饰,就是You'd better make...