刚刚从博客园看了这篇。把代码在Visual Studio Code中试过一遍，感觉对看懂前任测试的多线程项目更有点信心了。
Blocks the calling thread until itself terminetes
ManualResetEvent event=new ManualResetEvent(false);
阻塞当前线程
程序学累了缓缓脑子背单词
appeal[əˈpi:l] 呼吁
sleeve [sli:v] 袖子 sleeveless 无袖的
underscore 强调，印证
A rescuer makes his way down at the entrance to a cave complex where 12 boys and their soccer coach went missing