homework done on time will lead to better grades

问题描述:

homework done on time will lead to better grades
这里怎么只能用done,用be done 不行么,这句话的句子成分是怎样的.homework done on time做主语么

这是定语从句 初三才学 done on time 用来修饰homework
homework( (that)done on time) will lead to better grades
homework done on time是个名词短语 是主语 ,如果加be 就成一个句子了.