设计一个可以模拟渡船等待时间的系统。具体描述为有客车和货车需要乘坐渡船，一班渡船10分钟，可以上10辆车，并且规定每上4辆客车可以上1辆货车，若客车不足则以货车代替。要求对这一情景进行模拟，计算出客车和货车的平均等待时间。-Ferries designed to simulate a system latency. Specifically described as having buses and trucks need to take the ferry, ferry 10 minutes intervals, can the 10 cars, and requires that every passenger can last four on a truck, if insufficient places passenger van instead. This scenario requires the simulation of calculating the average passenger waiting time and lorries.