（一）that和which在指物的情况下一般都可以互换, 但在下列情况下, 一般用that而不用which。
（1）先行词为all, everything, nothing, something, anything, little, much 等不定代词时。
I am sure she has something（that）you can borrow.
（2）先行词被all, every, no, some, any, little, much等修饰时。
I’ve read all the books that are not mine.
（3）先行词被序数词或最高级修饰时。
