On the first morning he went out for a walk用on?
问题描述：
On the first morning he went out for a walk用on?
答
on 对,在morning,afternoon,evening前面有形容词修饰的时候用介词on,或者说：在具体某一天的前面用介词on,比如：
on a cold morning 在一个寒冷的早上