pandemics的例句（pandemics在句子中的用法）

• Previous pandemics have been characterized by waves of activity spread over months. 以往大流行的特点是一波接一波的流行持续数月之久.
• Since then, there have been a total of eight cholera pandemics. 从那时开始, 霍乱大流行总共爆发过8次.
• Periods when diseases spread around the world are called pandemics. 疾病在全世界范围内传播时期称为大流行.