There are appropriate and inappropriate times to use them. They can be very useful for checking your answers. B. Check the specifics of the problem or question. C. Remember that on multiple choice exams your first response is often your best response. So don't change your anser unless you have a good reason.
Many students change their answers to incorrect ones.
Proofread your exam. Allow yourself the whole test period to finish the exam. Do not allow those who leave early to bother you. They often are not the ones who do best. A. Remain clear, calm, confident and psotive.