Dentist: I'm sorry, madam, but I'll have to charge you twenty-five dollars for pulling your son's tooth. Mother: Twenty-five dollars! But I thought you only charged five dollars for an extraction. Dentist: I usually do. But your son yelled so loud, he scared four other patients out of the office. 牙科医生：对不起，夫人，为给您的儿子拔牙，我得收二十五美元。 母亲：二十五美元！可是我知道您拔一颗牙只要五美元呀？ 牙科医生：是的。但是您儿子这么大声地叫唤，他都吓跑四位病人了。