Begin your response by echoing the question
If you echo the question, you are more likely to write a response that answers the question because the question will usually spark your thinking along the right lines. For example, assume the test question asks, "If the reaction had been present, what would we have observed?" If you start your response with, "If the reaction had been present, we would have observed…," you are more likely to get right to descriptive details based on what you saw. Similarly, a test question such as, "Why would the key point you chose be the most effective?" calls for an answer that begins, "This key point is the most effective because…." The "because" sets you up immediately to get at the rationale behind your thinking.
Many teachers also prefer to have students write complete sentences when they answer essay questions on tests, so echoing the question gives you a head start on a complete sentence in your response.