一个英语谜语 what is four feet on the four feet waiting for four feet

what is four feet on the four feet waiting for four feet的意思是什么东西是四只脚在四只脚上等待四只脚?答案是A cat on a chair waiting for a mouse一只猫在一把椅子上等老鼠 猫是四只脚,椅子是四只脚,老鼠也是...