1.absence from 缺席,不在 如：
His long absence from work delayed his promotion.
他长期不上班，把他的提升给耽误了。
2. absence of 缺乏 如：
In the absence of my commanding officer, I acted on my own initiative.
指挥官不在场, 我主动见机行事。
In the absence of their teacher the class was in a state of anarchy.
教师不在, 班上一片混乱.
