If not, make the necessary changes. Check your paragraph and sentence structures. Check your grammar, spelling, punctuation, and capitalization very carefully. The easiest way to get a bad grade on a paper is to have several errors in these areas. Instructors will not tolerate these types of errors.
Words are very important.
Avoid the use of too many simple and over used words. Use a thesaurus regularly and add some color to your paper, but do not overdo it. Be sure that you know the words that you substitute, or you may be using them in the wrong context. Use quotes only when absolutely necessary. Ask yourself if paraphrasing is possible and if it would serve your purposes better.