translation.en: And the reason for this shape is that at the very beginning, let's say one or two people are infected, or affected by the thing and then they affect, or infect, two people, who in turn affect four, eight, 16 and so forth, and you get the epidemic growth phase of the curve.
translation.zh: 形成这种形状的原因是这样的，在一开始， 假设一两个人 受到影响， 然后他们去影响两个人， 然后就是四个，八个，十六个，等等， 这样你就得到了这个曲线的传播增长阶段。