string(240) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%B8%AD%E5%9B%BD%E5%89%8D10%E5%90%8D%E5%8F%91%E8%BE%BE%E5%9F%8E%E5%B8%82 => Failed to connect to 14.18.117.71 port 38069: Connection refused"
中国前10名发达城市
