Your paper is on the material dealing with an angel's cognition of material things, discussed by St. Thomas explicitly in Summa Theologiae 1, q. 57.  (As preparation for q. 57, you should first read qq. 54-56, which you will have to do anyway for the course.)  St. Thomas also discusses some of the issues taken up in q. 57 in the following places available on line in English translation:  

a. 1:  Summa Contra Gentiles 2, 99; De Veritate, q. 8, a. 8
a. 2:  Summa Contra Gentiles 2, 100; De Veritate q. 8, a. 11 and q. 10, a. 5
a. 3:  Summa Contra Gentiles 3, 154; De Veritate, q. 8, a. 12
a. 4:  De Veritate, q. 8, a. 9

Your task is to explain in a well-thought-out and coherent way the main conclusions that St. Thomas reaches in q. 57 and, in a general way, his reasoning in support of these conclusions.  That is, the paper is meant to be an exegetical paper that captures the distinctiveness of angelic cognition of material things, both in their natures and as individuals, and, in general, how angelic cognition of material things differs from God's cognition of them (see esp. q. 14, aa. 5-6) and from human cognition of them (see esp. q. 84, a. 1, 2, 6 and 7).  

Notice that I have pushed the due date back to October 2, the Feast of the Guardian Angels, who have promised to help you with the paper.