string(233) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%B8%80%E5%BB%BA%E6%95%99%E6%9D%902021%E7%89%88%E6%94%B9%E5%8A%A8 => Failed to connect to 14.18.117.71 port 38041: Connection refused"
一建教材2021版改动
