She is not the cheerfuf girl that she was.为什么只能用that引导,而不能用w

She is not the cheerfuf girl that she was.为什么只能用that引导,而不能用w It is/was not until...that从句,为什么从句不能用when引导 the city which she lives in is far away 为什么which不能用that? she is not the girl that she used to be This is the reason that he gave to me.w为什么只能用that The girl was so f____ that she could not move. This is the longest train that i have ever seen.为什么引导词不能用whi who is the girl （that）is crying.为什么不能用which? who is that?it must be Mary.为什么不能用she? 定语从句中什么时候引导词只能用that不能用which,什么时候只能用which不能用that? she is an honest girl who frankly__ that what she said was w She is the girl whom I went with there.中whom能用that代替吗?This i