center on something
also center around something— phrasal verb with center us/ˈsen·tər/verb [ T ]
to have as the main subject or interest:
The discussion centered on how students develop reading comprehension.
英语词典包含110679条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。