同学你好，该知识点来自沪江网校《英语初级进阶【微信专享班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学你好~

Be absent on 表示某人在某个具体的日期或时间缺席了某件事情，比如：

She was absent on Monday due to an illness. (她因为生病所以星期一缺席了。)
He is absent on the first day of the conference. (他在会议的第一天缺席了。)


Be absent from school 则表示某个学生缺席了学校的课程或者没来学校，比如：

Tom was absent from school yesterday. (汤姆昨天没来学校。)
Mary has been absent from school for a week due to a family emergency. (玛丽因为家庭紧急情况已经缺席学校一周了。)

总之，be absent on 强调某人缺席的具体时间，而be absent from school 则强调某个学生没来学校或者缺席了学校的课程。

祝同学学习进步~