似乎当我通过命令行（使用sudo apt-get someapp）安装应用程序时，该应用程序不会出现在 Ubuntu 软件列表中。 是否有可能让此类应用程序出现在那里？
运行评论中的命令，它会更新，然后我看到这个：
...
All packages are up to date.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used.
GPG error: http://dl.google.com/linux/chrome/deb stable Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 78BD65473CB3BD13
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used.
GPG error: http://dl.google.com/linux/earth/deb stable Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 78BD65473CB3BD13
W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/Release.gpg The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 78BD65473CB3BD13
W: Failed to fetch http://dl.google.com/linux/earth/deb/dists/stable/Release.gpg The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 78BD65473CB3BD13
W: Some index files failed to download. They have been ignored, or old ones used instead.
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package software-center is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'software-center' has no installation candidate
All packages are up to date.
N: Skipping acquire of configured file 'main/binary-i386/Packages' as repository 'http://dl.google.com/linux/earth/deb stable InRelease' doesn't support architecture 'i386'
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package software-center is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'software-center' has no installation candidate