The discovery of the cowpox vaccination let the danger of vaccination more less, and cost lest.牛痘术的发明使种痘的危险性更小, 花费也降到最低,故而很快在全世界推广开来.In nineteen century, Enligh doctor Pearson came to Macao to spread the cowpox vaccinati...

cowpox的音标：cowpox的英式发音音标为：['kaʊpɒks]cowpox的美式发音音标为：['kaʊpɑks]...

n.牛痘...