定语从句中的关系副词能否用that替换?

Question

定语从句中的关系副词能否用that 替换?

Answer 1

应该是这样的：
1 I know the factory WHERE she works.
变成that就是：I know the factory THAT she works in.(这里的介词 in 不能少.)
2 They are talking about the day WHEN they will go to London.
==They are talking about the day ON WHICH they will go to London.(这里只能用which不能用that,因为有介词在前面.）