string(254) "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%94%A8hz%E4%B8%8Ebps%E8%A1%A8%E7%A4%BA%E7%9A%84%E5%8C%BA%E5%88%AB => Failed to connect to 125.88.227.171 port 38062: Connection refused"
带宽用hz与bps表示的区别
