我运行sudo apt-get update时遇到了以下错误，但是我发现了类似的问题，但并不能帮助我。 实际上我需要解决这个问题。
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/trusty/Release Unable to find expected entry 'restricted/source/Sources' in Release file (Wrong sources.list entry or malformed file) W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/trusty/Release Unable to find expected entry 'universe/source/Sources' in Release file (Wrong sources.list entry or malformed file) E: Some index files failed to download. They have been ignored, or old ones used instead.
我在/etc/apt/source.list没有看到/etc/apt/source.list任何内容，实际上它来自哪里。
任何人都可以提出整洁的方式来解决这个错误