Comment upon them. They are not a substitute for your own thinking and expression. They must be footnoted or endnoted and the source must appear in your bibliography. Each essay is a unit, thus all paragraphs must be linked one to another so that there are no breaks in thought. The essays are too short for chapter divisions.
Contractions are colloquial.
Avoid them in formal writing. One book plus annotations in the syllabus cannot teach everything about such a complex subject as modern art. Therefore, you should do extra reading. Consult the list of Suggested Additional Reading at the end of this course guide.