doctor: how many ears and eyes does a cat have?
医生：一只猫有几个耳朵和眼睛？
patient: two of each.
病人：都是两个。
doctor: and how many legs does it have?
医生：那么它有几条腿呢？
patient: say, doctor, haven't you ever seen a cat?
病人：我说，医生，难道你从来没有见过猫吗？