A rich American went into a shop in London. He wanted very much 21 tobuy a nice-looking watch. He saw a watch and liked it so much that he decided to buy it. But the owner of the shop asked five hundred dollars for it. 22 While the American was hesitating, a young man suddenly came into the shop, took 23 the watch out of the owner’s hand and ran out with it. It all happened in 24 a few seconds. When the owner ran out 25 into the street, the young man had already 26 disappearedamong the people. The American went on. At the next corner, he saw 27 a young man with the stolen watch in his hand, "Do you want to buy a fine watch, sir?" he said in a low voice, "It’s only a hundred dollars.""The young man doesn’t know I saw him 28 robbing the watch just now," he thought. The American paid at once and went happily back to his room with the watch. He told his friend about the fine watch. His friend 29 had a look at the watch and started to shout immediately. He said, "You are a fool. This watch is worth only ten dollars. I’m 30 sure the shop owner and the young man planned all this together."