Though the same thing happens to me as well even though I choose different servers:

eagle@...:~$ sudo apt-get update
[sudo] password for eagle: 
Ign http://mirrors.sohu.com precise InRelease                                  
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Get:2 http://ppa.launchpad.net precise Release [11.9 kB]                       
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Hit http://mirrors.sohu.com precise-updates/main Sources                       
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Hit http://mirrors.sohu.com precise-updates/main i386 Packages                 
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Hit http://mirrors.sohu.com precise-updates/main TranslationIndex              
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Hit http://ppa.launchpad.net precise/main Sources                              
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Get:3 http://ppa.launchpad.net precise/main Sources [2,650 B]                  
Get:4 http://ppa.launchpad.net precise/main i386 Packages [2,206 B]            
Ign http://ppa.launchpad.net precise/main TranslationIndex                     
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Hit http://mirrors.sohu.com precise-security/main Sources                      
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Hit http://mirrors.sohu.com precise-security/main i386 Packages                
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Hit http://ppa.launchpad.net precise/main i386 Packages                        
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Hit http://mirrors.sohu.com precise/main Translation-en                        
Hit http://mirrors.sohu.com precise/multiverse Translation-en                  
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Ign http://archive.canonical.com precise/partner Translation-en_US             
Hit http://mirrors.sohu.com precise-updates/universe Translation-en            
Hit http://mirrors.sohu.com precise-backports/main Translation-en              
Hit http://mirrors.sohu.com precise-backports/multiverse Translation-en        
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Ign http://archive.canonical.com precise/partner Translation-en                
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Ign http://extras.ubuntu.com precise/main Translation-en_US                    
Hit http://mirrors.sohu.com precise-proposed/multiverse Translation-en         
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Ign http://extras.ubuntu.com precise/main Translation-en                       
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100% [Connecting to dl.google.com (74.125.128.190)]^Ceagle@eagle-Studio-XPS-1640:~$ ^C
eagle@eagle-Studio-XPS-1640:~$ sudo apt-get update
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Ign http://ppa.launchpad.net precise Release.gpg                               
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Ign http://archive.canonical.com precise/partner TranslationIndex              
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Hit http://mirrors.sohu.com precise-security/main Sources                      
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Ign http://extras.ubuntu.com precise/main Translation-en_US                    
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Ign http://extras.ubuntu.com precise/main Translation-en                       
Hit http://mirrors.sohu.com precise-proposed/restricted i386 Packages          
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Hit http://mirrors.sohu.com precise-proposed/multiverse i386 Packages          
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Err http://ppa.launchpad.net precise/main Sources                              
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Hit http://mirrors.sohu.com precise-proposed/multiverse TranslationIndex       
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Hit http://mirrors.sohu.com precise/main Translation-en                        
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Ign http://ppa.launchpad.net precise/main Translation-en_US                    
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Ign http://ppa.launchpad.net precise/main Translation-en_US                    
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Hit http://mirrors.sohu.com precise-proposed/main Translation-en               
Ign http://ppa.launchpad.net precise/main Translation-en_US                    
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Hit http://mirrors.sohu.com precise-proposed/universe Translation-en    
Ign http://dl.google.com stable InRelease                               
Err http://dl.google.com stable Release.gpg      
  Unable to connect to dl.google.com:http: [IP: 74.125.128.91 80]
Ign http://dl.google.com stable Release
Ign http://dl.google.com stable/main TranslationIndex
Err http://dl.google.com stable/main i386 Packages
  Unable to connect to dl.google.com:http: [IP: 74.125.128.91 80]
Err http://dl.google.com stable/main Translation-en_US
  Unable to connect to dl.google.com:http: [IP: 74.125.128.91 80]
Err http://dl.google.com stable/main Translation-en
  Unable to connect to dl.google.com:http: [IP: 74.125.128.91 80]
W: Failed to fetch http://ppa.launchpad.net/ubuntu-clamav/ppa/ubuntu/dists/precise/main/source/Sources  404  Not Found

W: Failed to fetch http://ppa.launchpad.net/ubuntu-clamav/ppa/ubuntu/dists/precise/main/binary-i386/Packages  404  Not Found

W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/Release.gpg  Unable to connect to dl.google.com:http: [IP: 74.125.128.91 80]

W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/main/binary-i386/Packages  Unable to connect to dl.google.com:http: [IP: 74.125.128.91 80]

W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/main/i18n/Translation-en_US  Unable to connect to dl.google.com:http: [IP: 74.125.128.91 80]

W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/main/i18n/Translation-en  Unable to connect to dl.google.com:http: [IP: 74.125.128.91 80]

E: Some index files failed to download. They have been ignored, or old ones used instead.