string(328) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%B8%8B%E9%9D%A2%E5%93%AA%E4%BA%9B%E6%98%AF%E5%B8%B8%E7%94%A8%E7%9A%84%E4%BC%81%E4%B8%9A%E7%BD%91%E7%AB%99%E5%9C%A8%E7%BA%BF%E6%8E%A8%E5%B9%BF%E6%96%B9%E6%B3%95 => Failed to connect to 61.171.74.35 port 38027: Connection refused"
下面哪些是常用的企业网站在线推广方法
