string(275) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E7%AE%80%E8%BF%B0%E7%BD%91%E7%AB%99%E7%9A%84%E6%8E%A8%E5%B9%BF%E6%96%B9%E5%BC%8F%E6%9C%89%E5%93%AA%E4%BA%9B => Failed to connect to 101.91.112.32 port 38195: Connection refused"
简述网站的推广方式有哪些
