We are always told that time is precious so that we shall cherish it. Even though most of us know the necessity of making use of time, when we start our plans, we find that time is limited. Where has the time gone, we always feel confused about it. Actually, it is the lack of efficiency that makes people feel time is not enough. It is in need of improving efficiency. Most students can't focus their mind on study because they think of all kinds of temptations, such as delicious food and computer games. If they can finish task quickly, then they can do other things. It is the motivation to improve efficiency.