string(328) "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%E5%92%8C%E9%80%9F%E7%8E%87%E5%9C%A8%E8%AE%A1%E7%AE%97%E6%9C%BA%E7%BD%91%E7%BB%9C%E4%B8%AD%E7%9A%84%E5%8C%BA%E5%88%AB%E6%98%AF%E4%BB%80%E4%B9%88 => Failed to connect to 14.116.215.7 port 38225: Connection refused"
带宽和速率在计算机网络中的区别是什么
