将Linux中的更新终端更改为US

我怎样才能每次都换成我们。我在Linux终端上更新

错误：

: Failed to fetch http://ph.nl.archive.ubuntu.com/ubuntu/dists/trusty/InRelease  
W: Failed to fetch http://ph.nl.archive.ubuntu.com/ubuntu/dists/trusty-updates/InRelease  
W: Failed to fetch http://ph.nl.archive.ubuntu.com/ubuntu/dists/trusty-backports/InRelease  
W: Failed to fetch http://ph.nl.archive.ubuntu.com/ubuntu/dists/trusty/Release.gpg  Could not resolve 'ph.nl.archive.ubuntu.com'
W: Failed to fetch http://ph.nl.archive.ubuntu.com/ubuntu/dists/trusty-updates/Release.gpg  Could not resolve 'ph.nl.archive.ubuntu.com'
W: Failed to fetch http://ph.nl.archive.ubuntu.com/ubuntu/dists/trusty-backports/Release.gpg  Could not resolve 'ph.nl.archive.ubuntu.com'
W: Some index files failed to download. They have been ignored, or old ones used instead.

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$sudo您最喜欢的编辑器/etc/apt/sources.list

，并将域更改为

us.archive.ubuntu.com