string(231) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=21%E5%B9%B4%E4%B8%80%E5%BB%BA%E6%95%99%E6%9D%90%E6%94%B9%E7%89%88 => Failed to connect to 61.171.74.35 port 38041: Connection refused"
21年一建教材改版
