English preposition exercises

One could tell atby his looks that he was tired.
"Hamlet" was written atby Shakespeare.
It is useful to have all one's reference books close atby hand.
She looked atby him.
They arranged to meet atby the theatre tonight.
I will have finished this work atby Saturday.
Tell me atby least one thing.
You won't find him atby home; he is gone out.
He should have more sense than that atby his age.
All this work is done atby hand.