某人用力F抬起放在水平地面上的一匀质杠杆AB的B端,F方向始终竖直向上,如图所示

题型:不定项选择

问题:

某人用力F抬起放在水平地面上的一匀质杠杆AB的B端,F方向始终竖直向上,如图所示,则在抬起的过程中

[ ]

A. F逐渐变大

B. F逐渐变小

C. F保持不变

D. 无法确定

考点:杠杆的平衡条件
题型:不定项选择

能源的开发、利用与人类社会的可持续发展息息相关,怎样充分利用好能源是摆在人类面前的重大课题.

I.已知:Fe2O3(s)+3C(石墨)=2Fe(s)+3CO(g)△H=akJ•mol-1

CO(g)+1/2O2(g)=CO2(g)△H=bkJ•mol-1

C(石墨)+O2(g)=CO2(g)△H=ckJ•mol-1

则反应:4Fe(s)+3O2(g)=2Fe2O3(s)的焓变△H=______kJ•mol-1

Ⅱ.(1)依据原电池的构成原理,下列化学反应在理论上可以设计成原电池的是______(填序号).

A.C(s)+CO2(g)=2CO(g)

B.NaOH(aq)+HCl(aq)=NaCl(aq)+H2O(l)

C.2H2O(l)=2H2(g)+O2(g)

D.CH4(g)+2O2(g)=CO2(g)+2H2O(l)

若以KOH溶液为电解质溶液,依据所选反应可以设计成一个原电池,请写出该原电池的电极反应.

负极:______,

正极:______.

(2)二氧化氯(ClO2)是一种高效安全的自来水消毒剂.ClO2是一种黄绿色气体,易溶于水.实验室以NH4Cl、盐酸、NaClO2为原料制备ClO2流程如下:

已知:电解过程中发生的反应为:

NH4Cl+2HCl

通电
.
.
NCl3+3H2↑;假设NCl3中氮元素为+3价.

①写出电解时阴极的电极反应式______.

②在阳极上放电的物质(或离子)是______.

③除去ClO2中的NH3可选用的试剂是______(填序号)

A.生石灰B.碱石灰C.浓H2SO4D.水

④在生产过程中,每生成1molClO2,需消耗______molNCl3

题型:不定项选择

以下哪种疾病不属于口腔变态反应性疾病()。

A.血管神经性水肿

B.接触性口炎

C.药物性口炎

D.斯-约综合征

E.Riga病

题型:不定项选择

The main purpose of Paragraph 2 is to ______.

A.answer an objection that some readers may raise to Paragraph 1

B.guard against the possibility that you have read Paragraph 1

C.contradict the idea of Paragraph 1

D.show more optimistic than Paragraph 1

题型:不定项选择

阅读理解

     In spite of the uncertainty of the economy, the movie industry has been stricken by a box-office

outburst. Suddenly it seems as if everyone is going to the movies, with ticket sales this year up 17.5

percent, to $1.7 billion.

     And it is not just because ticket prices are higher. Attendance has also jumped, by nearly 16 percent. If

that pace continues through the year, it would amount to the biggest box-office increase in at least two

decades.

     Americans, for the moment, just want to hide in a very dark place. People want to forget their troubles,

and they want to be with other people. Helping feed the outburst is the mix of movies, which have been

more audience-friendly in recent months as the studios have tried to adjust after the discouraging sales of

more serious films.

     As she stood in line at the 18-screen Bridge theater complex here on Thursday to buy weekend tickets

for "Jonas Brothers: The 3D Concert Experience," Angel Hernandez was not thinking much about escaping

reality. Instead, Ms. Hernandez, a Los Angeles parking lot attendant and mother of four young girls, was

focused on one very specific reality: her wallet.

     "Spending hundreds of dollars to take them to Disneyland is ridiculous right now," she said. "For $60

and some candy money I can still be a good mom and give them a little fun."

     A lot of parents may have been thinking the same thing Friday, as "Jonas Brothers" sold out more than

800 theaters, and was expected to sell a powerful $25 million or more in tickets.

     The film industry appears to have had a hand in its recent good luck. Over the last year or two, studios

have released movies that are happier, scarier or just less depressing than what came before. After poor

results for a rush of serious dramas built around the Middle East, Hollywood got back to comedies.

1.Which of the following is not a reason for the improvement of the movie industry?

A. A growing number of people are going to the cinema.

B. People are richer with the development of economy.

C. More comedies are made than serious films.

D. People have to pay more to watch a movie.

2.Ms. Hernandez purchased the movie tickets because _____.

A. she tried to escape reality                          

B. she was a crazy movie fan

C. she was fond of Disneyland                        

D. she wanted to please her kids

3.According to the text, which of the following number is not used to describe the shooting up of the 

movie industry?

A.17.5%              

B. $1.7 billion                

C. $60                

D. $25 million

4.The passage is developed mainly by _____.

A. presenting the effect and analyzing the causes        

B. following the order of time

C. describing problems and drawing a conclusion              

D. making comparison of ideas

题型:不定项选择

下列选项中对于建造(施工)合同的特征描述错误的是( )。

A.所建造资产的体积大、造价高
B.建造(施工)合同一般为可撤销合同
C.先有买主,后有标的,建造资产的造价在合同签订时就已经确定
D.资产的建设周期长,一般都要跨越一个会计年度,有的长在数年

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