string(231) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%B8%A6%E5%AE%BD%E7%9A%84%E8%AE%A1%E7%AE%97%E6%96%B9%E6%B3%95 => Failed to connect to 101.89.159.206 port 38075: Connection refused"
带宽的计算方法
