完形填空

　　A rich American went into a shop in London．He wanted very much 　　1　　 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．　　2　　 the American was hesitating(犹豫), a young man suddenly came into the shop, took 　　3　　 out of the owner's hand and ran out with it．It all happened in 　　4　　 seconds．When the owner ran out 　　5　　 the street, the young man had already 　　6　　 among the people．The American went on．At the next corner, he saw 　　7　　 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 　　8　　 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 　　9　　 a look at the watch and started to shout immediately．He said, “You are a fool．This watch isn't worth only ten dollars．I'm 　　10　　 the shop owner and the young man planned all this together．”