It was not, for example, until Louis Pasteur and Robert Koch proved the connection between germs and infection that doctors realised that to cure such diseases you had to kill the germs.

• 举例来说，在路易斯巴斯德和罗伯特?考科证明了细菌与感染之间的必然联系以前，医生们都没有意识到只有杀死病毒才能治愈疾病。