which的用法

用作疑问代词指哪一个，哪一些：Which is my seat？哪个座位是我的？(用做关系代词)那一个，那一些：He also had a gun with which to defend himself。他还有一把自卫用的枪。 He invited us to dinner,which was very kind of him. 他邀请我们吃晚饭，他这么做真是太客气了。 She was...