题干

如图,在矩形内有两个相邻的正方形,面积分别为2和4,则图中阴影部分的面积是____

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2 2 ﹣2

同类题1

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                                                                                Get a Thorough Understanding of Oneself.

    In all one's life lime it is oneself, that one spends the most time being with or dealing with.____.

    When you are going upwards in life you tend to overestimate yourself. It seems that everything you seek for is within your reach,____ It's likely that you think it wise for yourself to stay away from the outer world. Actually, to get a thorough understanding of oneself, you may as well keep the following tips in mind.

Gain a correct view of oneself.

    You may look forward hopefully to the future but be sure not to expect too much, for dreams can never be fully realized. You may be courageous to meet challenges but it should be clear to you where to direct your efforts.____

Self-appreciate.

    Whether you compare yourself to a towering tree or a blade of grass, a high mountain or a small stone, you represent a state of nature.____ If you earnestly admire yourself you'll have a real sense of self-appreciation.

____ In time of anger, do yourself a favor by releasing it in a quiet place so that you won't be hurt by its flames; in time of sadness, do yourself a favor by sharing it with your friends so as to change a bad mood into a cheerful one; in time of tiredness, do yourself a favor by getting a good sleep.

Get a full control of one's life.

    Then one will find one's life full of color and favor.

A. It has its own value.

B. Do oneself a favor when it's needed.

C. Do yourself a favor when you resist the attack of illness.

D. But it is precisely oneself that one has the least understanding of.

E. Especially if it is well within your reach, you are just too blind to see it.

F. When you are going downhill you tend to underestimate yourself for your own incompetence,

G. o long as you have a perfect knowledge of yourself, there won't be difficulties you can't overcome.

同类题5

能源、环境与人类生活和社会发展密切相关,研究它们的综合利用有重要意义.

(1)氧化还原法消除氮氧化物的转化如下:NO  NO2 N2

①反应I为:NO+O3=NO2+O2,生成11.2L O2(标准状况)时,转移电子的物质的量是____ mol.

②反应II中,当n(NO2):nCO(NH22=3:2时,反应的化学方程式是____  .

(2)硝化法是一种古老的生产硫酸的方法,同时实现氮氧化物的循环转化,主要反应为:

NO2(g)+SO2(g)⇌SO3(g)+NO(g)△H=﹣41.8kJ•mol1

已知:2SO2(g)+O2(g)⇌2SO3(g)△H=﹣196.6kJ•mol1

写出NO和O2反应生成NO2的热化学方程式____ .

(3)将燃煤废气中的CO2转化为二甲醚的反应原理为:2CO2(g)+6H2(g) CH3OCH3(g)+3H2O(g);该反应平衡常数表达式为K= ____ .

(4)合成气CO和H2在一定条件下能发生如下反应:CO(g)+2H2(g)⇌CH3OH(g)△H<0.

在容积均为V L的I、Ⅱ、Ⅲ三个相同密闭容器中分别充入a mol CO和2a mol H2,三个容器的反应温度分别为T1、T2、T3且恒定不变,在其他条件相同的情况下,实验测得反应均进行到t min时CO的体积分数υ(CO)%如右图所示,此时I、Ⅱ、Ⅲ三个容器中一定达到化学平衡状态的是____ ;若三个容器内的反应再经过一段时间后都达到化学平衡时,CO转化率最大的反应温度是____ .

(5)据报道以二氧化碳为原料,采用特殊的电极电解强酸性的二氧化碳水溶液可得到多种燃料,其原理如图所示.电解时,b极上生成乙烯的电极反应式为____ .