string(292) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%BA%8C%E7%BA%A7%E5%BB%BA%E9%80%A0%E5%B8%88%E6%95%99%E6%9D%90%E6%9B%B4%E6%96%B0%E6%97%B6%E9%97%B4%E6%98%AF%E5%A4%9A%E4%B9%85 => Failed to connect to 14.18.117.71 port 38093: Connection refused"
二级建造师教材更新时间是多久
