string(241) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=2021%E4%BA%8C%E5%BB%BA%E6%95%99%E6%9D%90%E6%9C%89%E5%8F%98%E5%8C%96%E5%90%97 => Failed to connect to 14.18.46.51 port 38206: Connection refused"
2021二建教材有变化吗
