同窗

例句：

1. 1. We are classmates, so we should help each other.
   我们是同学，所以应该互相帮助。
2. 2. He is a good friend to me, and I am his good friend to him.
   他是我的好朋友，我也是他的好朋友。
3. 3. They are good friends, and they always support each other.
   他们是好朋友，总是互相支持。