string(256) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%93%AA%E7%A7%8D%E5%B7%A5%E4%BD%9C%E8%87%AA%E7%94%B1%E5%BA%A6%E6%AF%94%E8%BE%83%E9%AB%98 => Failed to connect to 14.18.117.71 port 38093: Connection refused"
哪种工作自由度比较高
