string(283) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E7%9F%AD%E8%B7%AF%E4%B8%8E%E6%96%AD%E8%B7%AF%E7%9A%84%E7%8E%B0%E8%B1%A1%E6%9C%89%E5%93%AA%E4%BA%9B%E4%BE%8B%E5%AD%90 => Failed to connect to 14.18.117.71 port 38041: Connection refused"
短路与断路的现象有哪些例子
