Time is precious. Nobody can afford to waste time. Once time has gone by， it will never return. You can never turn the clock back. Time passes very quickly. In fact，people say time flies. Time and tide wait for no man. We should， therefore， make the best use of our time.
光阴似箭
时间是很宝贵的，谁都浪费不起时间。时间一旦消逝，就永不再回来。你永远也无法让时光倒流。时间过得很快，事实上，人们说光阴似箭。岁月不待人，因此，我们应该好好善用时间。