You really need to do some work on this in the following areas. See me.
Accuracy: Were the items that you chose actually from your text? How accurately did you describe the importance of these items? Were there items that you neglected that were actually more important?
Completeness: Is your collage FULL? Do you have images or writing covering the entire paper? Do you have at least 20 items? Did you include 2-3 sentences for each picture explaining what the item is and why it is important in the book?
Creativity:Is your collage visually appealing? Would it engage an audience? Is it colorful? Does it stand out?
Does the work represent your best effort? Did you put time and thought into this project? Is everything neatly done? Did you check mechanics and grammar in your writing?