string(369) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%9F%BA%E6%9C%AC%E7%9A%84%E7%BB%84%E7%BB%87%E7%BB%93%E6%9E%84%E5%BD%A2%E5%BC%8F%E6%9C%89%E5%93%AA%E4%BA%9B%2C%E7%AE%80%E8%A6%81%E8%AF%B4%E6%98%8E%E5%90%84%E8%87%AA%E7%9A%84%E4%BC%98%E7%BC%BA%E7%82%B9 => Failed to connect to 101.89.143.195 port 38175: Connection refused"
基本的组织结构形式有哪些,简要说明各自的优缺点
