string(276) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E4%B8%AD%E5%A4%AE%E9%93%B6%E8%A1%8C%E7%A5%A8%E6%8D%AE%E5%B1%9E%E4%BA%8E%E4%BB%80%E4%B9%88%E5%B7%A5%E5%85%B7 => Failed to connect to 101.89.166.210 port 38089: Connection refused"
中央银行票据属于什么工具
