Không thể định vị gói phần mềm-thuộc tính chung [đã đóng]

trên Ubuntu 15.04 của tôi (tôi đã nhận nó dưới dạng máy chủ ảo), tôi muốn cài đặt sự thống nhất ... nhưng từng bước để nắm bắt các thuộc tính phần mềm phổ biến, nhưng tôi đã nhận được:

 sudo apt-get install software-properties-common
Reading package lists... Done
Building dependency tree... Done
E: Unable to locate package software-properties-common

Ai đó có thể giúp làm thế nào để tiếp tục?

/# cat /etc/apt/sources.list
deb http://archive.ubuntu.com/ubuntu vivid main restricted universe
deb http://archive.ubuntu.com/ubuntu vivid-updates main restricted universe
deb http://security.ubuntu.com/ubuntu vivid-security main restricted universe multiverse
deb http://archive.canonical.com/ubuntu vivid partner

/# sudo apt-get update
Get:1 http://security.ubuntu.com vivid-security InRelease [64.4 kB]
Get:2 http://archive.ubuntu.com vivid InRelease [218 kB]
Get:3 http://archive.canonical.com vivid InRelease [10.3 kB]
Get:4 http://archive.canonical.com vivid/partner amd64 Packages [2978 B]
Get:5 http://security.ubuntu.com vivid-security/main amd64 Packages [166 kB]
Ign http://archive.canonical.com vivid/partner Translation-en
Get:6 http://security.ubuntu.com vivid-security/restricted amd64 Packages [11.2 kB]
Get:7 http://archive.ubuntu.com vivid-updates InRelease [64.4 kB]
Get:8 http://security.ubuntu.com vivid-security/universe amd64 Packages [66.3 kB]
Get:9 http://archive.ubuntu.com vivid/main amd64 Packages [1364 kB]
Get:10 http://security.ubuntu.com vivid-security/multiverse amd64 Packages [6045 B]
Get:11 http://security.ubuntu.com vivid-security/main Translation-en [79.8 kB]
Get:12 http://security.ubuntu.com vivid-security/multiverse Translation-en [2743 B]
Get:13 http://security.ubuntu.com vivid-security/restricted Translation-en [2774 B]
Get:14 http://security.ubuntu.com vivid-security/universe Translation-en [41.2 kB]
Get:15 http://archive.ubuntu.com vivid/restricted amd64 Packages [15.4 kB]
Get:16 http://archive.ubuntu.com vivid/universe amd64 Packages [6485 kB]
Get:17 http://archive.ubuntu.com vivid/main Translation-en [793 kB]
Get:18 http://archive.ubuntu.com vivid/restricted Translation-en [4228 B]
Get:19 http://archive.ubuntu.com vivid/universe Translation-en [4456 kB]
Get:20 http://archive.ubuntu.com vivid-updates/main amd64 Packages [260 kB]
Get:21 http://archive.ubuntu.com vivid-updates/restricted amd64 Packages [13.6 kB]
Get:22 http://archive.ubuntu.com vivid-updates/universe amd64 Packages [127 kB]
Get:23 http://archive.ubuntu.com vivid-updates/main Translation-en [125 kB]
Get:24 http://archive.ubuntu.com vivid-updates/restricted Translation-en [3112 B]
Get:25 http://archive.ubuntu.com vivid-updates/universe Translation-en [74.6 kB]
Fetched 14.5 MB in 28s (506 kB/s)
Reading package lists... Done

Sau đó sudo apt-get update, tôi đã có thể cài đặt software-properties-common.