He has often said,one ___(be) never to old too learn.what & Why?

问题描述:

He has often said,one ___(be) never to old too learn.
what & Why?

is
就是一个事实啊~~该用什么时态就是什么时态,和前面一句没关系
one 第三人称单数

is
不用过去式!是名言警句,就像有人说地球绕太阳转一样,不用过去式!

can be
他常说,活到老学到老。

has been
前面是现在完成时,后面也用现在完成时

is
成语:one is never too old to learn 活到老,学到老
成语普遍规律用一般时态

is
意思是:一个人无论年龄多大,都可以学习。
算是谚语吧。