Some teachers are used to tear off the answer keys. Some students disagree with it. They think the answer keys can check the answers in time and correct the wrong ones which are good for them to improve their innovative ability. But the other students hold a different opinion. They believe that tearing off the answer keys can prevent students from copying the answers. It also can help them thinking independently and strengthening their confidence. Some teachers are used to tear off the answer keys. Some students disagree with it. They think the answer keys can check the answers in time and correct the wrong ones which are good for them to improve their innovative ability. But the other students hold a different opinion. They believe that tearing off the answer keys can prevent students from copying the answers. It also can help them thinking independently and strengthening their confidence.