定语从句~急1.he belives that earth is unlikely to be the only planet （whose ） life has developed gradually.括号里为啥不用which,他哪个地方不缺主语和宾语,不是用which做主语吗?括号里是where，不是which

因为句子当中缺成分

用where.
这个跟句法无关,
跟句意有关
里面意思是地球上的生命
是个地点
而不是地球的生命

这里whose修饰life,作life的定语.引导定语从句的关系代词中只有wose才可以作定语.
题中whose life合起来作这个定语从句的主语.
whose可以转换成of which.这句话可以说成：
He belives that earth is unlikely to be the only planet the life of which has developed gradually.
或：
He belives that earth is unlikely to be the only planet of which the life has developed gradually.
或：
He belives that earth is unlikely to be the only planet which the life of has developed gradually.
人教版高中英语必修（二）附录中好像有相似的例子.