string(242) "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%E7%AE%A1%E7%90%862021%E6%95%99%E6%9D%90%E5%8F%98%E5%8C%96 => Failed to connect to 14.18.117.71 port 38133: Connection refused"
一建管理2021教材变化
