单选It was on January the ____he came here last time

题目

单选It was on January the ____he came here last time
It was on January the ____he came here last time.
A thirty-one that
B thirty first
C thirty-one when
D thirty first when
为什么?

答案

D 日期肯定是序数词 when用作时间状语从句,先行词就是前面的日期,that用在这里是没有依据的