Linux 如何解决W：某些索引文件下载失败。它们被忽略了，或者使用了旧的

我使用的是Ubuntu 18.04.4，当我运行“sudo apt get update”时，会出现以下错误。

Err:1 http://repo.mysql.com/apt/ubuntu bionic InRelease                        
  Could not connect to repo.mysql.com:80 (23.213.169.17), connection timed out
Err:2 http://ny-mirrors.evowise.com/ubuntu bionic InRelease                    
  Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:4b3). - connect (101: Network is unreachable) Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:5b3). - connect (101: Network is unreachable) Could not connect to ny-mirrors.evowise.com:80 (104.22.5.179), connection timed out Could not connect to ny-mirrors.evowise.com:80 (104.22.4.179), connection timed out
Err:3 http://ny-mirrors.evowise.com/ubuntu bionic-updates InRelease            
  Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:4b3). - connect (101: Network is unreachable) Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:5b3). - connect (101: Network is unreachable)
Err:4 http://ny-mirrors.evowise.com/ubuntu bionic-backports InRelease          
  Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:4b3). - connect (101: Network is unreachable) Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:5b3). - connect (101: Network is unreachable)
Err:5 http://ny-mirrors.evowise.com/ubuntu bionic-security InRelease           
  Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:4b3). - connect (101: Network is unreachable) Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:5b3). - connect (101: Network is unreachable)
Err:6 http://ppa.launchpad.net/samoilov-lex/aftl-stable/ubuntu artful InRelease
  Cannot initiate the connection to ppa.launchpad.net:80 (2001:67c:1560:8008::15). - connect (101: Network is unreachable) Could not connect to ppa.launchpad.net:80 (91.189.95.83), connection timed out
Err:7 http://ppa.launchpad.net/vikoadi/ppa/ubuntu bionic InRelease             
  Cannot initiate the connection to ppa.launchpad.net:80 (2001:67c:1560:8008::15). - connect (101: Network is unreachable)
Err:8 http://packages.microsoft.com/repos/vscode stable InRelease
  Connection failed [IP: 104.214.230.139 80]
Err:9 http://archive.canonical.com/ubuntu bionic InRelease
  Connection failed [IP: 91.189.91.15 80]
Reading package lists... Done
W: Failed to fetch http://ny-mirrors.evowise.com/ubuntu/dists/bionic/InRelease  Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:4b3). - connect (101: Network is unreachable) Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:5b3). - connect (101: Network is unreachable) Could not connect to ny-mirrors.evowise.com:80 (104.22.5.179), connection timed out Could not connect to ny-mirrors.evowise.com:80 (104.22.4.179), connection timed out
W: Failed to fetch http://ny-mirrors.evowise.com/ubuntu/dists/bionic-updates/InRelease  Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:4b3). - connect (101: Network is unreachable) Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:5b3). - connect (101: Network is unreachable)
W: Failed to fetch http://ny-mirrors.evowise.com/ubuntu/dists/bionic-backports/InRelease  Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:4b3). - connect (101: Network is unreachable) Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:5b3). - connect (101: Network is unreachable)
W: Failed to fetch http://archive.canonical.com/ubuntu/dists/bionic/InRelease  Connection failed [IP: 91.189.91.15 80]
W: Failed to fetch http://ny-mirrors.evowise.com/ubuntu/dists/bionic-security/InRelease  Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:4b3). - connect (101: Network is unreachable) Cannot initiate the connection to ny-mirrors.evowise.com:80 (2606:4700:10::6816:5b3). - connect (101: Network is unreachable)
W: Failed to fetch http://ppa.launchpad.net/samoilov-lex/aftl-stable/ubuntu/dists/artful/InRelease  Cannot initiate the connection to ppa.launchpad.net:80 (2001:67c:1560:8008::15). - connect (101: Network is unreachable) Could not connect to ppa.launchpad.net:80 (91.189.95.83), connection timed out
W: Failed to fetch http://repo.mysql.com/apt/ubuntu/dists/bionic/InRelease  Could not connect to repo.mysql.com:80 (23.213.169.17), connection timed out
W: Failed to fetch http://ppa.launchpad.net/vikoadi/ppa/ubuntu/dists/bionic/InRelease  Cannot initiate the connection to ppa.launchpad.net:80 (2001:67c:1560:8008::15). - connect (101: Network is unreachable)
W: Failed to fetch http://packages.microsoft.com/repos/vscode/dists/stable/InRelease  Connection failed [IP: 104.214.230.139 80]
W: Some index files failed to download. They have been ignored, or old ones used instead.

我尝试了一些解决办法，但毫无帮助