HTTP/1.1 200 OK Server: ************ Date: Thu, 02 Dec 2021 02:19:25 GMT Content-Type: application/pdf Content-Length: 0 Connection: keep-alive X-Frame-Options: SAMEORIGIN Last-Modified: Tue, 25 May 2021 08:04:07 GMT Accept-Ranges: bytes ETag: "0-5c322f8618bc0-gzip" Content-Language: zh-CN