string(260) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%BA%8C%E5%BB%BA2021%E7%89%88%E6%95%99%E6%9D%90%E4%BB%80%E4%B9%88%E6%97%B6%E5%80%99%E5%87%BA => Failed to connect to 14.18.117.71 port 38220: Connection refused"
二建2021版教材什么时候出
