[语法] 非谓语（很简单的问题,不过总是不明白）
To be strict with students is to be responsible to them.
To be strict with students为什么不能换成“being strict with students”?不可以看做是动名词作主语吗?
minssing the last bus means walking home.这里不久是V-ING开头吗?有什么区别