补充省略部分,分析句子
问题描述：
补充省略部分,分析句子
The professor can hardly find sufficient grounds on which to base his arguments in favor of the new theory.
请帮忙补充on which 后面省略的成分.它是做定语的么?
答
The professor can hardly find sufficient grounds on which （he can ) base his arguments in favor of the new theory.which (he can) to base……定语从句的主语跟主句主语一致的时候可以省略，省略了主语要用不定式短语。