题目内容：

An old man whose eyesight was failing comes to stay in a hotel, a bottle of whisky in his hand. On the wall was a fly he took for a nail．The moment he tried to hang the bottle on it, they fell and broke．When the landlady discovered what had been happened, she decided to do him favor．The next morning when he was out, the hotel worker hammered a nail exact where the “fly” had been．Before the old man came back, the smell of the whisky reminded him the accident．Looking at the spot what he thought the “fly” was again, he was so angry that he slapped it with all his strengths．On hearing the loud cry, the landlady rushed in．To her surprise, the poor old man was sitting on the floor with the palm of his hand bleed．