One day the staff members of a zoo called a meeting to discuss the problem--how to deal with the kangaroos that were found out of the cage. They came to the conclusion that the cage was placed too low and decided to raise it from one to two meters high. But the next day the kangaroos were still at large and they again raised the cage to three meters.
Quite beyond their expectation the next morning they saw the kangaroos still free to go about. They were alarmed and determined to go to all the length by raising the cage to the height of ten meters.
Later a giraffe, while chatting with some kangaroos, asked them, “Do you think they will go on raising your cage?
“Hard to say, said a kangaroo, “if they continue forgetting to fasten the cage door.
一天动物园工作人员开会讨论这个问题——如何应对发现了笼子的袋鼠。他们的结论是，笼放得太低，决定提高这一到两米高。但是第二天，袋鼠仍然在逃，他们又高度加高到三米。
没想到第二天早晨，他们看见袋鼠仍然可以自由地去。他们担心，决定去所有的长度将笼子的高度加高到十米。
后来一只长颈鹿和几只袋鼠，而聊天，问他们，“你们认为他们会继续加高你们的笼子?“
“很难说，一只袋鼠说，“如果他们继续忘记关门。