string(271) "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%9C%BA%E7%94%B5%E7%8E%8B%E5%85%8B%E7%B2%BE%E8%AE%B2%E7%9A%84%E8%AE%B2%E4%B9%89 => Failed to connect to 101.89.117.144 port 38208: Connection refused"
2021二建机电王克精讲的讲义
