An Alarm Clock
A young man went to a mountain village for his holiday. One night he stayed at a small hotel near a train station.
Before going to bed， he went to the owner of the hotel and said to the old man， “ Excuse me， sir. Will you please wake me up at a quarter to five？ I'm going to take the five o'clock train tomorrow morning. ”
“ Oh， sorry， ” the owner said， “ I am afraid I can't. I don't get up that early. ”
The young man started to go back to his room when he stopped and asked， “ Do you have an alarm clock？ That would help me. ”
“ Yes， here it is， young man. ”
The young man took the clock happily and thanked the old man. But when he looked at it carefully， there appeared to be something wrong with it.
“ Does it ring on time？ ” he asked the old man.
“ Sure！ Just shake it when it's time to get up， and it'll ring. ”