string(298) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=2020%E5%B9%B4%E6%B3%A8%E5%86%8C%E5%AE%89%E5%85%A8%E5%B7%A5%E7%A8%8B%E5%B8%88%E9%87%91%E5%B1%9E%E5%86%B6%E7%82%BC%E7%AD%94%E6%A1%88 => Failed to connect to 125.88.227.171 port 38114: Connection refused"
2020年注册安全工程师金属冶炼答案
