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%E5%8E%86%E5%8F%B2%E6%8C%81%E6%9C%89%E7%BE%8E%E5%9B%BD%E5%9B%BD%E5%80%BA => Failed to connect to 101.89.117.144 port 38022: Connection refused"
中国历史持有美国国债
