Now, we call that number...

现在我们将这个数字称作
...the R-nought.

基本传染数
R stands for the reproductive rate of the virus.

传染数是指病毒的繁殖率
Any ideas what that might be for this?

跟这事有什么关系吗
How fast it multiplies depends on a variety of factors.

病毒增殖的速度取决于一系列因素
The incubation period, how long a person is contagious.

潜伏期一个人被感染了多久
Sometimes people can be contagious without even having symptoms.

有时候被感染的人不会有任何症状
We need to know that too.

这一点我们也需要知道
And we need to know how big the

我们还需要知道
population of people susceptible to the virus might be.

易感人群会有多少
So far that appears to

目前为止似乎
be everyone with hands, a mouth and a nose.

人人都可能被感染