string(274) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%AE%BD%E5%B8%A6%E9%80%9F%E7%8E%87%E5%8D%95%E4%BD%8D%E6%98%AF%E6%AF%94%E7%89%B9%E4%BD%8D%E6%AF%8F%E7%A7%92 => Failed to connect to 14.18.117.71 port 38069: Connection refused"
宽带速率单位是比特位每秒
