a)　在there be 句型中，只用that，不用which。
b)　在不定代词，如：anything, nothing, the one, all, much, few, any, little等作先行词时，只用that，不用which。
c)　先行词有the only, the very修饰时，只用that。
d)　先行词为序数词、数词、形容词最高级时，只用that。.
e)　先行词既有人，又有物时。
举例：
All that is needed is a supply of oil.
所需的只是供油问题。
Finally, the thief handed everything that he had stolen to the police.
那贼最终把偷的全部东西交给了警察。