实质追索在自然界里,有一类现象,人们无法预先知道它是否发生或不发生,这种在一定条件下,可能发生也可能不发生的事件,称为不确定事件(随机事件),简称为事件.通俗地说,一个事件发生的可能性大小,叫做该事件发生的概率.怎样才能确定一个事件发生的概率呢?例如,“掷一枚硬币,出现 There is a phenomenon in the natural world where people cannot know in advance whether it has occurred or not. This kind of event, which may or may not occur under certain conditions, is called an indefinite event (random event), abbreviated as Event. In layman’s terms, the probability of an event occurring is called the probability of the event. How can we determine the probability of an event? For example, "a coin is thrown and appears