They主语 rushed over谓语 to help the man目的状语 whose car had broken dwon.定语
Nobody主语 wants谓语 the house宾语 whose roof has fallen in.定语在第二句中：定语whose roof has fallen in不是修饰主语吗？？怎么在这是修饰宾语the house??这里的whose roof 指房子的屋顶是修饰宾语the house定语可以修饰宾语？？定语从句进一步说明宾语的情况那怎么不说它是补语，又没有修饰主语它是用来限定哪一所房子的