流行病

例句：

1. 1. The flu is a common cause of epidemics in many countries.
   流感是许多国家常见的流行病。
2. 2. The doctor advised everyone to get vaccinated against the new virus.
   医生建议每个人都接种疫苗以预防这种新病毒。
3. 3. The outbreak of the pandemic has caused widespread panic and fear.
   大流行的爆发引起了广泛的恐慌和恐惧。