HTTP/1.1 200 OK Server: nginx/1.16.1 Date: Fri, 05 Mar 2021 00:35:54 GMT Content-Type: application/pdf Content-Length: 0 Connection: keep-alive X-Frame-Options: SAMEORIGIN Last-Modified: Thu, 14 May 2020 18:52:31 GMT Accept-Ranges: bytes ETag: "0-5a5a032e879c0-gzip" Content-Language: zh-CN