string(258) "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%E6%8C%81%E6%9C%89%E7%9A%84%E7%BE%8E%E5%80%BA%E5%92%8C%E7%BE%8E%E5%85%83 => Failed to connect to 101.89.159.206 port 38075: Connection refused"
中国持有的美债和美元
