string(266) "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%E5%92%8C%E6%96%AD%E8%B7%AF%E6%9C%89%E4%BB%80%E4%B9%88%E7%89%B9%E7%82%B9%E5%92%8C%E4%BD%9C%E7%94%A8 => Received HTTP code 403 from proxy after CONNECT"
短路和断路有什么特点和作用
