string(249) "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%E7%A5%A8%E6%8D%AE%E7%9A%84%E4%B8%BB%E8%A6%81%E5%8A%9F%E8%83%BD => Failed to connect to 101.89.143.195 port 38175: Connection refused"
中央票据的主要功能
