以 root 身份登录后，我输入apt-get update，它给了我：
E: Malformed entry 51 in list file /etc/apt/sources.list (URI parse)
E: Malformed entry 1 in list file /etc/apt/sources.list.d/docker.list (Component)
E: The list of sources could not be read.
它出什么问题了？
看到很多相关的答案我输入了代码： sudo -H gedit /etc/apt/sources.list
然后它显示：
# deb cdrom:[Ubuntu 16.10 _Yakkety Yak_ - Release amd64 (20161012.2)]/ yakkety 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/ yakkety main restricted
# deb-src http://us.archive.ubuntu.com/ubuntu/ yakkety main restricted
## …