WORLD CIVILIZATION

Detailed explanation-1: -They have compared these results to the overland transmission speeds of the twentieth-century bubonic plague and have found that the Black Death travelled at 1.5 to 6 kilometres per day-much faster than any spread of Yersinia pestis in the twentieth century.

Detailed explanation-2: -You get pneumonic plague when Y. pestis bacteria gets into your lungs. It’s the least common and most dangerous type of plague. Pneumonic plague can spread from person to person through coughing and sneezing, just like the common cold.