Sam is in (the) second grade.

萨姆读二年级。

《牛津词典》

I flunked math in second grade.

我二年级时数学不及格。

《牛津词典》

Once in the second grade, our teacher had each of us race across the monkey bar.

二年级的时候，老师让我们每个人比赛越过攀爬架。

youdao

Second grade teacher Alison Kerr says the main goal is to engage children in the learning process.

VOA: special.2011.03.10

The first grade corresponds to the row player, me in this case, and the second grade in each box corresponds to the column player, my pair in this case.

单元格内第一个成绩是我的成绩,每个单元格第二个成绩是,我对手的成绩

耶鲁公开课 - 博弈论课程节选

And the question is, so how many pigs does he have, and how many chickens does he have? Wow. What a deep problem, right? But you're going to see why we're going to use this in a second. So you know how to solve this, this is a fifth-grade problem, right?

为了避免歧义，这些猪和鸡都是健全的,现在问题是它到底有多少只猪和鸡呢？,多深刻的一个问题啊，对吗？,但是你将要看到的是,我们为什么要举这个例子,你知道如何解答这个问题？

麻省理工公开课 - 计算机科学及编程导论课程节选

Under Dodd, the AAU has added national championships down to the second grade level.

FORBES: AAU President Bobby Dodd: The Next Alleged High-Profile Youth Sports Pedophile

Excerpt: When I was promoted to detective second grade and was working plainclothes, my problems began.

FORBES: Fact And Comment

Second grade drama aside, many parents struggle with how to accommodate a variety of dietary restrictions.

FORBES: Back to School: Special Food Needs