下面这句话有一处错误,请找出来并改正.

问题描述:

下面这句话有一处错误,请找出来并改正.
Kevin swims in the river hours ago.

Kevin swims(改为swam) in the river hours ago.
几小时前凯文在这条河里游泳.
因为时间状语是过去的,因为谓语动词swim要改为过去式.