How to install suggested packages in apt-get

suggests and recommends are not the same thing.

Package A depends on Package B if B absolutely must be installed in order to run A. In some cases, A depends not only on B, but on a version of B. In this case, the version dependency is usually a lower limit, in the sense that A depends on any version of B more recent than some specified version.

Package A recommends Package B, if the package maintainer judges that most users would not want A without also having the functionality provided by B.

Package A suggests Package B if B contains files that are related to (and usually enhance) the functionality of A.

See The Debian GNU/Linux FAQ for details.

By default, apt-get installs recommended packages.

Your option --install-suggests adds in the suggested packages and their suggested dependencies.

--install-suggests
    Consider suggested packages as a dependency for installing.
    Configuration Item: APT::Install-Suggests.

see apt-get(8).

I found out why the recommended packages in my question were not included in the packages to be installed. It's because those recommended packages do not exist in the repositories. I tried to install a random package, I chose sudo apt-get install googleearth-package. It did not show the Recommended packages section (which means they are already included in the NEW packages to be installed section). To confirm this, I ran sudo apt-get --no-install-recommends install googleearth-package, and surely enough the Recommended packages section revealed itself. As for the suggested packages, I guess I won't be using --install-suggests because that just installs the suggested packages and their suggested packages.