软件工程16新生 vim 什么apt-get安装包没了怎么解决啊求大神

zeng@ubuntu:~$ sudo apt-get install vim
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package vim is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'vim' has no installation candidate
因为自己是新手所以这些地方不太懂只是在官网下载了ubuntu16.04的镜像文件装的虚拟机
求大神帮助怎么解决啊!