Alan lives in a big city and he is a doorman of a store. Every day, many people pass (经过)the door, and some of them stop and ask him, "What's the time?" "At first, he is happy and tells them the time. But after a few months, Alan: feels tired of answering(厌倦回答) the same question again and again.
"You may buy a clock. ""His wife says to him one day. He thinks it's a good idea. So he buys a clock after work and puts it on the wall. "Now people don't ask me about the time because they can see the clock. "He thinks happily. But after that, a lot of people stop, look at the clock and ask Alan, "Is that clock right?"
