On the exam, will we be able to mark two answers to come back to? I am having a hard time remembering which answers I marked as viable when I come back to them.

to recognize a sufficient condition, it has helped me to think "does this imply anything about the necessary condition" . For example, if its a cat, does it imply that its a mammal - yes, thus cat is sufficient condition for mammal. Does mammal imply that its a cat? no, thus not a sufficient condition