Sometimes, parts of the body stop working properly and we get sick. This may happen because the body becomes infected by germs from outside, or because something is damaged inside the body. Doctors do tests and use their knowledge and experience to find out what is wrong with their patients.
    有時，我們身體的某些部位完全停止工作，我們就病了。這可能是因為我們的身體被外界的細菌感染了，或者是因為身體的內部的某些部位損傷了了。醫(yī)生進行檢查并用他們的知識和經驗做找出病人的問題。