1.   If one can notice the absence of something one must already know what it is for things to be absent.

2.   Joe noticed his absence in the night, shining a torch to avoid stepping on him but finding no sign of Fred.

3.   Paul was praying that no one had noticed his absence.

4.   It was when they were assembling for dinner that they had noticed her absence.

5.   And he noticed the absence of the Secret Service.

6.   At least she noticed his absence.

7.   But no one has really noticed his absence because Benjamin and Lou Merloni have done the job so well.

8.   For those who noticed my absence, I will publish a brief account of my recent whereabouts.

9.   Hobbs has put on the dog by taking his guests overseas for a Vineyard lunch, promising to have us back in Boston before the boss notices our absence.

10.   I had noticed the absence of usual summer gifts from his garden.