说明：  使用事件对象，建立10个线程，线程一激活线程3，线程3运行后，激活线程5，以此类推，运行顺序为1，3，5，7，9，2，4，6，8，10
(Using event objects, ten threads are created. Once threads 3 are activated, threads 5 are activated after threads 3 are running, and so on, in order of 1, 3, 5, 7, 9, 2, 4, 6, 8, 10)