a cat's ability to survive falls is based on fact 请问to survive falls是一个词组还是什么,

问题描述:

a cat's ability to survive falls is based on fact 请问to survive falls是一个词组还是什么,
怎么去科学理解,或这是什么语法现象

这句话的主语部分是"A cat's ability to survive falls",其中 ability是主语中心语,所以谓语动词用单数形式(is).谓语是"be based on “ 以…为基础;建立在…基础上宾语是"fact"--事实难点在于对"survive"这个单词的...