The mobile phone makes us happy老师说可以,We use the mobile phone to da many things说要加复数,

题目

The mobile phone makes us happy老师说可以,We use the mobile phone to da many things说要加复数,
但是We have a enough sleep或life不需要,它都有a了,为什么不用复数
考试时候老师让写,进入高中后应懂得的事,我写We should obey the rules in our shools老师说没有S,为什么,进入高中后我们不是有各自不同的高中了吗
有一次我想说Famous buildings are often made by teams,not a person老师认为可以,但那不是许多的单独的人吗,这与英语语法不符啊
说一下什么时候用复数

答案