Why should you always try to identify your purpose before you begin reading?

You suspect that this article has left out some facts that might lead the reader to believe that someone else made the star-spangled banner. what is the best way to verify this? by consulting a variety of sources by disregarding the article entirely by writing a letter to the editor of the publication that printed the article by reading various historical accounts by verifying the opinions

In marigolds, what does lizabeth’s parents interaction in the middle of the night mainly reveal about lizabeth’s father?

Although the account is in good standing at this point in time. is this sentence incomplete or complete?