string(257) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%8F%82%E8%80%83%E6%96%87%E7%8C%AE%E5%BC%95%E7%94%A8%E6%A0%BC%E5%BC%8F%E8%BD%AC%E6%8D%A2 => Failed to connect to 101.91.112.32 port 38221: Connection refused"
参考文献引用格式转换
