string(258) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E7%9F%AD%E4%BF%A1%E8%90%A5%E9%94%80%E7%9A%84%E4%BD%9C%E7%94%A8%E6%98%AF%E4%BB%80%E4%B9%88 => Failed to connect to 101.89.159.206 port 38100: Connection refused"
短信营销的作用是什么
