The time we have is usual limited. However, even an hour is of great valuable. We should make full use of your time to do useful things. As students, we mustn’t study hard so as to serve for our society and our nation in the future. But it is pity that there are a lot of people who didn’t know the importance of time. They spend their valuable time smoke and drinking. They don’t realize that wasting time is the same as wasting a part of their life. Remember, don’t put off which you can do today until tomorrow.