试了几个都提示：
W: Failed to fetch http://mirrors.ustc.edu.cn/archive.raspberrypi.org/debian/dists/jessie/main/binary-armhf/Packages 404 Not Found [IP: 202.141.160.110 80]
W: Failed to fetch http://mirrors.ustc.edu.cn/archive.raspberrypi.org/debian/dists/jessie/ui/binary-armhf/Packages 404 Not Found [IP: 202.141.160.110 80]
E: Some index files failed to download. They have been ignored, or old ones used instead.
W: Failed to fetch http://mirrors.ustc.edu.cn/archive.raspberrypi.org/debian/dists/jessie/main/binary-armhf/Packages 404 Not Found [IP: 202.141.160.110 80]
W: Failed to fetch http://mirrors.ustc.edu.cn/archive.raspberrypi.org/debian/dists/jessie/ui/binary-armhf/Packages 404 Not Found [IP: 202.141.160.110 80]
E: Some index files failed to download. They have been ignored, or old ones used instead.
