当我尝试使用 apt update 进行更新时，出现以下错误。
Err:10 http://ppa.launchpad.net/danielrichter2007/grub-customizer/ubuntu bionic InRelease
Could not connect to ppa.launchpad.net:80 (91.189.95.83), connection timed out Could not connect to ppa.launchpad.net:80 (2001:67c:1560:8008::15), connection timed out
Err:11 http://ppa.launchpad.net/js-reynaud/kicad-5.1/ubuntu bionic InRelease
Unable to connect to ppa.launchpad.net:http:
Err:12 http://ppa.launchpad.net/tista/plata-theme/ubuntu bionic InRelease
Unable to connect to ppa.launchpad.net:http:
Err:13 http://ppa.launchpad.net/ubuntubudgie/backports/ubuntu bionic InRelease
Unable to connect to ppa.launchpad.net:http:
Err:14 http://ppa.launchpad.net/zeal-developers/ppa/ubuntu bionic InRelease
Unable to connect to ppa.launchpad.net:http:
Fetched 7,502 B in 31s (238 B/s)
Reading package lists...
Building dependency tree...
Reading state information...
1 package …