关于英语完形填空的问题~

题目

关于英语完形填空的问题~
rent research on battery life shows that the battry in out newest mobile phone (performs) better that those in similar products.
我想问下 不是说一个句子只有一个动词吗?这里的shows,和performs 不是2个动词了吗?为什么是performs而不是performing呢

答案

这是个复合句,由主句rent research on battery life shows和从句 that the battry in out newest mobile phone (performs) better that those in similar products.
构成.show是主句里的谓语动词,后面是由that引导的宾语从句,perform是这个宾语从句里的动词.