Long long ago, there was a big cat in the house. He caught many mice while they were stealing (偷) food.
One day the mice had a meeting to talk about the way to deal with their common enemy (共同的敌人). A young mouse stood up, and said he had a good idea. "We could tie a bell around the neck of the cat. Then when he comes near, we can hear the sound of the bell, and run away.
Everyone agreed, but an old wise mouse got up and said, "That is all very well, but who will tie the bell to the cat?" The mice looked at each other, but nobody spoke.
