My fourth-grade students and I hope for world peace when our time capsule is opened in one hundred years.

我的四年级学生和我希望当我们的时间胶囊在一百年后被打开时，世界和平。

My younger brother is in fourth grade this year.

我弟弟今年上四年级。

Fourth grade math is a bit challenging for him.

四年级的数学对他来说有点难。

She won the school spelling bee in fourth grade.

她在四年级时赢得了学校的拼字比赛。

Students in fourth grade start learning more about science.

四年级的学生开始学习更多的科学知识。

We went to the museum when we were in fourth grade.

我们在四年级的时候去了博物馆。

I still remember my fourth-grade social studies project.

我还记得我四年级的社会研究项目。

One day in fourth grade, our teacher gave us a project in class.

四年级的一天，老师在课堂上给我们布置了一个课题。

He had to repeat the fourth grade.

他读四年级时留级一年。

The boy was kept back in the fourth grade.

男孩在四年级时留级.