be at school

基本解释

Why are you hanging around the supermarket when you are supposed to be at school?
既然現在是上課時間，你就應該在校上課，怎麽會在超市閑逛呢？
engsky.dongge.blog.163.com
We will be at school tomorrow.
我們明天將會在學校。
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.
雖然所有父母都希望孩子的學校足夠安全，但這種做法太過了，感覺好像是將孩子送到了一所戒備森嚴的高級監獄。

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.
你們要牢記這一點,因爲之後,我們會談到這個問題,做的實騐時,我會反複提到這個內容。
麻省理工公開課 - 媒躰、教育、市場課程節選
It's really nice, as you can tell, to be at a school in such a great location.
所以，學校能夠在這麽好的一個位置是很值得高興的。
關於舊金山大學校園 - SpeakingMax英語口語達人