string(238) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E6%8F%90%E5%8D%87%E7%BD%91%E7%BB%9C%E9%80%9F%E7%8E%87%E6%96%B9%E6%B3%95 => Failed to connect to 14.18.117.71 port 38133: Connection refused"
提升网络速率方法
