We are warned not to waste time because time 1 will never return. I think it quite 2. What does time look 3? Nobody knows, and we can't see it or touch it and no 4 of money can buy it. Time is abstract(抽象的), so we have to 5 about it.

    Time passes very quickly. Some students say they don't have 6 time to review their lessons. It is 7 they don't know how to make use of their time. They waste it in going to theatres or playing, and 8 other useless things. Why do we study every day? Why do we work? Why do most people 9 take buses instead of walking? The answer is very 10. We wish to save time because time is 11.

    Today we are living in the 21^st century. We 12 time as life. When a person dies, his life ends. Since life is short, we must 13 our time and energy to our study so that we 14 be able to work and live well in the future. Laziness is the 15 of time, for it not only brings us 16, but also does other 17 to us. If it is necessary for us to do our work today, 18 us do it today and not 19 it until tomorrow. Remember that time is much more 20.

阅读下面文字，完成下列小题。

       被人误解的时候,能微微一笑，这是一种素养；受委屈的时候,能坦然一笑，这是一种① ______；吃亏的时候,能开心一笑，这是一种豁达；无奈的时候,能达观一笑，这是一种②___________；危难的时候,能泰然一笑，这是一种大气；被轻蔑的时候,能平静一笑，这是一种③______；伤心的时候,能轻轻一笑，这是一种撒脱。人们常犯最大的错误,是对陌生人太客气,而对亲密的人太  kē刻。把这个坏习惯改过来，天下太平。帮助人是一种崇高，理解人是一种豁达，原谅人是一种美德，__A___。月圆是诗，月缺是花，仰首是春，俯首是秋。