The kinds of viruses that we get when we have colds are very good at infecting the respiratory system.

我们感冒时感染的各种感冒病毒,就非常精于感染呼吸系统

耶鲁公开课 - 生物医学工程探索课程节选

So, they don't start killing all the cells in your respiratory system; they only kill the cells that are harboring the virus.

所以它们不会杀死所有呼吸系统内的细胞,只杀死那些被病毒感染的细胞

耶鲁公开课 - 生物医学工程探索课程节选