string(275) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%BC%9A%E5%91%98%E5%88%B6%E8%90%A5%E9%94%80%E7%9A%84%E4%BC%98%E7%BC%BA%E7%82%B9%E6%98%AF%E4%BB%80%E4%B9%88 => Failed to connect to 101.91.112.32 port 38221: Connection refused"
会员制营销的优缺点是什么
