be at school

基本解释

Why are you hanging around the supermarket when you are supposed to be at school?
既然现在是上课时间，你就应该在校上课，怎么会在超市闲逛呢？
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We will be at school tomorrow.
我们明天将会在学校。
blog.sina.com.cn
All parents want their children to be safe at school but this is over the top. It's like sending your kids to a high-security prison.
虽然所有父母都希望孩子的学校足够安全，但这种做法太过了，感觉好像是将孩子送到了一所戒备森严的高级监狱。

Recently, researchers at the University of Colorado School of Medicine found that the effects of the surgery may not be long-lasting.
So I think it is important to keep this in mind and I'm gonna be coming back to this a number of times as we talk about the experiments we were doing at the Soen School of management.
你们要牢记这一点,因为之后,我们会谈到这个问题,做的实验时,我会反复提到这个内容。
麻省理工公开课 - 媒体、教育、市场课程节选
It's really nice, as you can tell, to be at a school in such a great location.
所以，学校能够在这么好的一个位置是很值得高兴的。
关于旧金山大学校园 - SpeakingMax英语口语达人