When we were in middle school.
何必写student呢.
就这样就行了.
倒是可以减小改动.
“when we were middle school students.”

we 是复数的啊.
...你在做什么题啊.
别忘了这不是一句完整的话.
是半句恩!
如果把它当成完整的句子话肯定就是错的.