Smallpox threatens the world During the protracted war with microorganisms, a series of epidemics-smallpox, bubonic plague, syphilis, typhoid, and tuberculosis-struck Europe, India, and China, steadily increasing the natural resistance to these diseases among Eurasian populations.
天花、鼠疫、梅毒、傷寒、肺結核......，不論歐洲還是印度、中國，各地疫疾不斷，而和微生物長期交鋒、「千錘百鍊」的結果，則讓這些地區的人類免疫力大大增強。