Answer:
The author's purpose is to persuade.
Explanation:
We know this because it states "urging young athletes not to use steroids." This is persuasive, as a persuasive tone always seems to convince or plead the audience to do/not to do something. In this case, it is not using steroids.
1) I like to run. (functions as a direct object)
2) I wanted to cook dinner for my parents. (functions as a direct object)
3) To fly an airplane is a dream of mine. (functions as a subject)
4) I cannot believe you knew to put out grits to attract ants! (functions as a direct object)
5) The fair is the place to go. (tells us which place)
Hope I was able to help. :)