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.

　　3. access to ……的入口,通路　　如：

　　The only access to the farmhouse is across the fields.

　　要到那农舍去唯有穿过田地。

　　She was forbidden access to the club.

　　人家不允许她到那个俱乐部去。

　　4. acquaintance with 相识,了解　如：

　　I have only a nodding acquaintance with Japanese.

　　我对日语仅略知一二。

　　The guide has some acquaintance with Italian.

　　导游懂得一点意大利语。

　　5. action on sth 对……的作用　　如：

　　Evidences of glacial action on the rocks

　　岩石上的冰河留下的痕迹