A curious guy goes to a pet shop to buy a parrot. There he sees a parrot with a red string tied to its left leg and a green string tied to it's right leg. He asks the owner the significance of the strings1. "Well, this is a highly trained parrot. If you pull the red string he speaks French; if you pull the green string he speaks German," replies the shop keeper. "And what happens if I pull both the strings?" our curious shopper inquires. "I fall off my perch2 you fool!!" screeches3 the parrot.有个人去宠物店买鹦鹉。在那里，他看见有只鹦鹉的左腿被红线系住，右腿则被绿线系住。对此他感到不解，于是他问该店的老板，老板回答说：“这只鹦鹉受过特殊的训练。如果拉红线，它就讲法语，拉绿线，它则讲德语。”这个好奇的人接着问，“要是我两条线都拉，会怎么样呢？”“我就会掉下来了，你这个傻瓜！！”鹦鹉尖叫着说。