Eddie and Ben are good friends and they help each other.(保持句意不变)
问题描述：
Eddie and Ben are good friends and they help each other.(保持句意不变)
答
Eddie and Ben are good friends who/that help each other.
定语从句，意思未变
答
Eddie and Ben are good friends who help each other.
Eddie and Ben are good friends that help each other.
答
and they 变成who