Plan your time allocation for answering and stick to it. Allocate time by the number of points assigned to a question, not the number of questions. If you are feeling anxious, do a short, easy item first. Be sure to check it again later when you are feeling calmer. If an item is ambiguous, begin with your interpretation of the meaning of the question.
Mere quantity is insufficient.
No answer guarantees no points. A partial answer may at least earn you something. Don't waste time on emotional reactions. Watch your time. Copy only with permission.