string(312) "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%BE%8E%E5%9B%BD%E5%9B%BD%E5%80%BA%E5%AF%B9%E6%88%91%E5%9B%BD%E6%9C%89%E4%BB%80%E4%B9%88%E5%BD%B1%E5%93%8D => Failed to connect to 101.89.159.206 port 38100: Connection refused"
中国持有美国国债对我国有什么影响
