How are the Presidential system in the United States with the Parliamentary system found in most European democracies expressions of the unique...

There are many possible ways to answer this.  I would
suggest that you check in your text or your notes to see if there is one specific answer
that you are required to come up with.

I would argue that
the differences in these two systems reflect the fact that American political culture is
generally more suspicious of the government than European political cultures are.  The
United States began its existence with a rebellion against heavy-handed government and
the political culture of the country reflects that beginning.  Americans do not trust
their government and therefore do not want to put too much power in the hands of any one
person or political party.  For this reason, they set up a system in which the executive
and the legislative are separate from one another and can check one
another.

The American presidential system, then, reflects
the fact that Americans trust their governments much less than Europeans traditionally
have.