阅读理解。 Someone says, 'Time is money.' But I think time is more important than money. Why? Because when money is spent, we can get it back. However, when time is lost, it'll never return. That is why we mustn't waste time. Even a second is very important. We should make full use of our time to do something useful. But it is a pity that many people don't know the importance of time. They spend their limited time smoking, drinking and playing cards. They don't know that wasting time means wasting some of their own lives. In a word we should save time. We shouldn't leave today's work for tomorrow. Remember: We have no time to lose. 51. Why does the writer say we mustn't waste time? A. Time is money. B. Time is expensive. C. Time never comes back when it's gone. 2. Why is time limited? A. To everyone life is limited. B. Money is limited. C. Most people don't know its importance. 3. How can we save time? A. Never smoke. B. Never drink. C. Finish work on time. 4. The writer feels _____ for the people playing cards always. A. sorry B. angry C. excited 5. What's the main idea of the passage? A. Time is important. B. Money is important. C. Time is more important than money.