collecting the things needed for school.

问题描述:

collecting the things needed for school.
needed for school 这是作things 的什么语
还有这句话还可以怎样表达.因为本人不理解这个表达

needed for school 这是作things 的定语
收集学校需要的材料.
材料是被学校需要,所以用needed
collecting the things that school ask for