I took a English exam

I took an English exam today afternoon.
It's name is Toeic. Do you know Toeic?
It is test for people who aren't  native English speakers.
In my country Korea, it is a very useful exam to get a job.
It is divided two parts. The first session is listening, the second is reading.
Its content is business writing. It isn't to improve speaking and writing skills.

Anyway my grade will be, good, haha.

And I have one question.
The and a, an, when are they used ??
Thanks for your correction.

<em>[Good job.  Use this site to learn about articles:</em>

<em>http://www.learnenglish.de/grammar/articlestext.html</em>;