复数： upperclassmen

I had met my first upperclassman .

我见过我的第一个学长。

" Heh-heh-heh , I get the whole information from the upperclassman . "

嘿-嘿-嘿，我从学长那儿得到了所有的消息

What were you thinking , breaking the nose of an upperclassman ?

你到底怎么想的?居然会打破一个高年级同学的鼻子?

Who is it ? An upperclassman from a school circle .

谁啊?学校的一个前辈.

The upperclassman and his underclass mothers learned together in cooking class .

高年级的学生和他的下层阶级的母亲一起在烹饪课上学习。