Не удалось apt-get update и не удалось найти ожидаемую запись источников. Ubuntu 16.04 LTS

Это то, что показывает терминал.

$ sudo apt-get update

Hit:1 http://ppa.launchpad.net/maarten-baert/simplescreenrecorder/ubuntu xenial InRelease
Hit:2 http://archive.ubuntu.com/ubuntu xenial-updates InRelease                
Hit:3 http://archive.ubuntu.com/ubuntu xenial InRelease                        
Hit:4 http://archive.ubuntu.com/ubuntu xenial-backports InRelease              
Hit:5 http://realsense-hw-public.s3.amazonaws.com/Debian/apt-repo xenial InRelease
Hit:6 http://security.ubuntu.com/ubuntu xenial-security InRelease              
Hit:7 https://typora.io/linux ./ InRelease                                     
Hit:8 http://packages.ros.org/ros/ubuntu xenial InRelease                      
Reading package lists... Done
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial/InRelease  Unable to find expected entry 'http://us.archive.ubuntu.com/ubuntu//source/Sources' in Release file (Wrong sources.list entry or malformed file)
E: Some index files failed to download. They have been ignored, or old ones used instead.

Я использую Ubuntu 16.04 LTS.

Ошибка: не удалось получить http://archive.ubuntu.com/ubuntu/dists/xenial/InRelease Не удалось найти ожидаемую запись ' http: //us.archive. ubuntu.com/ubuntu//source/Sources 'в файле Release (неверная запись sources.list или неверно сформированный файл)

Сайт не найден.

Я испробовал множество методов, таких как изменение источника обновления, изменение DNS и автоматическая очистка списка. Они не помогли мне. Надеюсь, что кто-то может решить мою проблему.

Большое спасибо!

мой список источников:

#deb cdrom:[Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2)]/ xenial main restricted

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://us.archive.ubuntu.com/ubuntu/ xenial main restricted
# deb-src http://us.archive.ubuntu.com/ubuntu/ xenial main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://us.archive.ubuntu.com/ubuntu/ xenial-updates main restricted
# deb-src http://us.archive.ubuntu.com/ubuntu/ xenial-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://us.archive.ubuntu.com/ubuntu/ xenial universe
# deb-src http://us.archive.ubuntu.com/ubuntu/ xenial universe
deb http://us.archive.ubuntu.com/ubuntu/ xenial-updates universe
# deb-src http://us.archive.ubuntu.com/ubuntu/ xenial-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
## team, and may not be under a free licence. Please satisfy yourself as to 
## your rights to use the software. Also, please note that software in 
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://us.archive.ubuntu.com/ubuntu/ xenial multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ xenial multiverse
deb http://us.archive.ubuntu.com/ubuntu/ xenial-updates multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ xenial-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://us.archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse
# deb-src http://us.archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu xenial partner
# deb-src http://archive.canonical.com/ubuntu xenial partner

deb http://security.ubuntu.com/ubuntu xenial-security main restricted
# deb-src http://security.ubuntu.com/ubuntu xenial-security main restricted
deb http://security.ubuntu.com/ubuntu xenial-security universe
# deb-src http://security.ubuntu.com/ubuntu xenial-security universe
deb http://security.ubuntu.com/ubuntu xenial-security multiverse
# deb-src http://security.ubuntu.com/ubuntu xenial-security multiverse

deb https://typora.io/linux ./
# deb-src https://typora.io/linux ./
deb http://realsense-hw-public.s3.amazonaws.com/Debian/apt-repo xenial main
# deb-src http://realsense-hw-public.s3.amazonaws.com/Debian/apt-repo xenial main