In the chapter 2 review, the first question is:
What is the significance of a form’s attribute? Of its attribute?
If I'm understanding the question correctly, the "Of its attribute?" clause has at least two corrections. One is that it is repetitive and not needed, the second is that "its" should be possessive, "it's" if the clause is supposed to be there. I believe the correct question should be, "What is the significance of a form’s attribute?"