string(247) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E7%BD%91%E9%80%9F%E4%B9%8B%E9%97%B4%E7%9A%84%E5%8D%95%E4%BD%8D%E6%8D%A2%E7%AE%97 => Failed to connect to 14.18.117.71 port 38093: Connection refused"
网速之间的单位换算
