Doctor: How many ears and eyes does a cat have?

Patient: Two of each.

Doctor: And how many legs does it have?

Patient: Say, Doctor, haven't you ever seen a cat?

医生：一只猫有几个耳朵和眼睛？

病人：都是两个。

医生：那么它有几条腿呢？

病人：我说，医生，难道你从来没有见过猫吗？