Command line 通过命令行安装指示灯不起作用

我刚刚访问了这个网站：并试图按照如何安装mint的教程进行操作。appache安装成功了。但是，当我粘贴以下代码来安装php时，它不起作用

sudo apt get安装php5 libapache2-mod-php5

这是我键入命令后显示的内容：

sidney-the-programmer sidney # sudo apt-get install php5 libapache2-mod-php5
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package libapache2-mod-php5 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

Package php5 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 'php5' has no installation candidate
E: Package 'libapache2-mod-php5' has no installation candidate

---

还有别的吗？我这边有什么问题吗？

错误信息是什么？@srael.zing。请检查编辑的问题。提前感谢再次下载！我想文件不见了