(1) 如果先行词是all, much, anything, something, nothing, everything, little, none等不定代词，关系代词一般只用that，不用which。例如： All the people that are present burst into tears. (2) 先行词有两个，既有人也有物，要用that。 We were talking about the persons and things that we remembered in our school.

关系代词that 和which的区别 

1.宜用that引导的定语从句