You must stop ( ),because it is bad for your

问题描述:

You must stop ( ),because it is bad for your
You must stop ( ),because it is bad for your health.
a.to smoke
b.smoke
c.to smoking
d.smoking
正确答案是D,为什么?还有为什么不可以选C?

stop+doing …是固定用法没有stoptodo…这个用法好的谢谢