low的比较级lower为什么不双写w再加er

因为low不是重读闭音节，ow是字母组合: lower

He belongs to the lower middle class.    他来自中产阶级下层。

The lower berth is more convenient.    下铺更为方便。

He would never lower himself by taking bribes.    他决不会贬低自己的身分接受贿赂的。

We have to lower our expenses.    我们得减少开支。

They lowered at each other without saying anything.    他俩无言以待地互皱眉头。