string(244) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=2020%E7%9B%91%E7%90%86%E6%A6%82%E8%AE%BA%E6%95%99%E6%9D%90%E5%8F%98%E5%8C%96 => Failed to connect to 101.89.117.144 port 38017: Connection refused"
2020监理概论教材变化
