一个经典的羊车游戏，有三个门，有一个后面有车，2个后面有羊，当你做选择时，主持人将其中一个有羊的门公布，你可以选择不改变，随机选择或改选另一个门，这个例子对mvc模式有很好的理解-Sheep a classic car games, there are three doors, one behind a car, two behind the sheep, when you choose, the host will be one of the doors have announced the sheep, you can choose not to change, random selection or election of another door, this example mvc pattern of well understood