string(337) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%B7%A5%E7%A8%8B%E7%9B%91%E7%90%86%E6%A6%82%E8%AE%BA%E7%AC%AC%E4%BA%8C%E7%89%88%E5%91%A8%E5%9B%BD%E6%81%A9%E8%AF%BE%E5%90%8E%E7%AD%94%E6%A1%88%E7%AC%AC%E5%9B%9B%E7%AB%A0 => Failed to connect to 14.18.117.71 port 38041: Connection refused"
工程监理概论第二版周国恩课后答案第四章
