Our teacher is always the first ___ and the last ___ in our school

问题描述:

Our teacher is always the first ___ and the last ___ in our school
A.come ,to leave B.to come,to leave c.coming,leaving D.come,leave
为什么选B?

be动词后面不能直接跟动词原形.第二个空的to也不可以省略.to do表示一种经常,频繁的状态.