大三大四的课程是最重要的，以专业为中心的学习真 正开始，老师与学生互动的研究教学开始密集。

Second two years are the most important, where the majority of major centered learning and professor-student interaction occurs.

youdao

在我的大学期间，我的本科学业中的,一些美好的回忆,是在我的大三大四期间,我参加了一个学校的研讨会。

While I was in college, part of the beauty and elegance of my undergraduate education was that between my junior and senior years I went on one of our college's seminars.

youdao

两年来我看到了他的不懈努力，看到他一点一滴的进步，看到他在无形中把本来比他优秀的大三大四的师兄师姐一点点的压下去。

For these two years, I witnessed his relentless efforts and constant progress and how he outran his senior schoolmates who were originally better than him.

youdao

While I was in college, part of the beauty and elegance of my undergraduate education was that between my junior and senior years I went on one of our college's seminars.

在我的大学期间，我的本科学业中的,一些美好的回忆,是在我的大三大四期间,我参加了一个学校的研讨会。

普林斯顿公开课 - 人性课程节选