string(246) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E6%8E%A8%E5%B9%BF%E7%9A%84%E5%BD%A2%E5%BC%8F%E5%8C%85%E6%8B%AC%E8%AE%B2%E5%BA%A7 => Failed to connect to 14.18.46.51 port 38044: Connection refused"
推广的形式包括讲座
