如图,△ABC是等腰直角三角形,∠ACB=90°,AB=AC,把△ABC绕点A按

题型:填空题

问题:

如图,△ABC是等腰直角三角形,∠ACB=90°,AB=AC,把△ABC绕点A按顺时针方向旋转45°后得到△AB'C',若AB=2,则线段BC在上述旋转过程中所扫过部分(阴影部分)的面积是(    )(结果保留π)。

考点:组合图形面积
题型:填空题

(6分)某化学兴趣小组的同学设计了如图所示的装置,探究影响化学反应速率的因素。

(1) 下图装置中使用注射器的优点是                  ,观察量筒中液体的体积时视线要与                              

(2)下面是用上述装置实验时,收集的相关数据:

实验

序号

H2O2溶液

的浓度/%

H2O2溶液

的体积/mL

MnO2

用量/g

温度/℃收集O2的体积/mL反应所需

的时间/s

520.120418
1020.12046
308/40264
308/60225
由实验①和②对比可知.化学反应速率与                             有关;

由实验③和④对比可知.化学反应速率与温度的关系是                         ;

(3)化学反应的实质是构成物质的微观粒子相互碰撞、结合的结果.化学反应速率与微观粒子的概率有关。试从微观角度解释“反应物浓度越大,化学反应速率越快”的原因:

                                                                     

(4)发现问题:实验时温度最难控制,反应一段时间后溶液的温度总是比起始时温度高,说明反应

        热量。

(5)继续探究:

除了该实验小组探究过的因素以外,你若还有其他影响反应速率的因素及探究方法.请写在下面。若正确.本题另奖励4分,本试卷总分不超过60分。

题型:填空题

小明问:“伯伯,您今年几岁?”伯伯说:“我与共和国同岁。”伯伯今年几岁?(  )  

A.50岁

B.65岁

C.58岁

D.63岁

题型:填空题

Changsha,

Hunan Province

May 6, 2010

Dear editor,

Under China’s current educational system, there are those who do nothing but study. They of course are thought to be model students.

But I feel that there is another type of student who, perhaps not as diligent (勤奋的) as the first type, uses his time more efficiently and achieves a lot academically.

Last year, a classmate of mine was accepted by a top university. It surprised all of us. It was because, unlike most of us, he didn’t spend too much of his time studying.

When I asked him the secret of his success, he said that the key was properly and scientifically arranging his time.

“ I spent a lot of time keeping fit and as a result, I was able to better concentrate (集中) on my class work.”

The moral of the story is: it isn’t necessary to sit at your desk all day long to get high academic (学术) grades.

Yours,

Zhang Zishu

小题1:What does the letter-writer (a reader) think leads to the fact that many students do nothing but study?

A.The present educational system.

B. People’s old ideas.

C.The teaching methods.

D.The parents of these students.小题2:It seems that this reader thinks        .

A.the first type of student is our model

B.the second type of students is our model

C.both types of students are worth learning from

D.neither of the two types of students are good小题3: The secret of his classmate’s success was        .

A.properly and scientifically arranging his time

B.spending a lot of time studying

C.doing nothing but studying

D.playing all the time小题4: The reader wrote the letter in order to        .

A.call on us to work even harder

B.cause people to think about how to study more efficiently

C.advise people to do research into his classmate’s success

D.criticize (批评) China’s educational system小题5:What would be the best to stand for the letter-writer’s opinion?

A.Secret of success.

B.China’s educational system needs changing.

C.Work while you work and play while you play.

D.Keep fit first.

题型:填空题

瓶颈物资的供应商关系策略,是将与瓶颈物资供应商的关系转换为()的关系。

A、一般物资的供应商

B、重要物资的供应商

C、战略物资的供应商

D、特殊物资的供应商

题型:填空题

菜肴的造型在装盘设计的时候主要遵循哪些基本法则?

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