mass epidemic的用法和样例：
例句
- The astronomical amount of death led to the declaration of a cholera epidemic in New York.
巨大的死亡人数导致纽约宣布霍乱大流行。 - Several epidemic influenza viruses leading to worldwide periodical pandemics all result from the genetic reassortment of different influenza viruses.
不同种属流感病毒通过基因重排产生变异病毒导致了多次周期性全球流感大流行。
