string(310) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%B8%AD%E5%9B%BD%E7%9A%84%E5%85%AC%E5%85%83%E5%89%8D%E4%B8%8E%E5%85%AC%E5%85%83%E5%90%8E%E6%98%AF%E6%80%8E%E6%A0%B7%E5%88%92%E5%88%86%E7%9A%84 => Failed to connect to 14.18.117.71 port 38220: Connection refused"
中国的公元前与公元后是怎样划分的
