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.
有时，我们身体的某些部位完全停止工作，我们就病了。这可能是因为我们的身体被外界的细菌感染了，或者是因为身体的内部的某些部位损伤了了。医生进行检查并用他们的知识和经验做找出病人的问题。