用that ,附：宜用that,不用which或who,whom的场合1. 当先行词是不定代词或被不定代词修饰时.如 Tell me everything that you know. / All the people that are working are my workmates. 2. 当先行词是序数词或被序...确实有第五条？嗯。。。而且在我印象中，先行词是数词时，后面还真没有过用which连接的情况~~O(∩_∩)O