string(238) "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%B0%B4%E5%88%A9%E5%AE%9E%E5%8A%A1%E6%95%99%E6%9D%90 => Failed to connect to 14.18.117.71 port 38220: Connection refused"
一建水利实务教材
