better to make friends than make enemeies.这句话为什么than后面用原型?than 不是介词么?为什么不用making?

问题描述:

better to make friends than make enemeies.
这句话为什么than后面用原型?than 不是介词么?为什么不用making?

It's better to do A than (to) do B
前后是对称的结构,有时把后面的to省略
如要用ing
Making friends is better than making enemies.