Age looks back on the happiness of youth.
问题描述：
Age looks back on the happiness of youth.
look back on是一个短语吗?不是的话,on起什么作用?
答
是短语,回忆的意思
look back on sth.on是介词,介词后面跟名词,look back 后面不能直接跟名词,因此用了on