60. What is the writer’s attitude toward Wilkins, Watson and Crick?   A. Disapproving.   B. Respectful.     C.  Admiring.    D. Doubtful.

答案  57.B  58.C  59.D  60.A

Passage 2

(09·重庆B篇)

How to Be a Winner

 Sir Steven Redgrave

 Winner of 5 Olympic Gold Medals

 “In 1997 I was found to have developed diabetes(糖尿病). Believing my career(职业生涯) was over, I felt extremely low. Then one of the specialists said there was to no reason why I should stop training and competing. That was it -the encouragement I needed. I could still be a winner if I believed in myself. I am not saying that it isn’t difficult sometimes. But I wanted to prove to myself that I wasn't finished yet. Nothing is to stand in my way.”

 Karen Pickering

 Swimming World Champion

 “I swim 4 hours a day, 6 days a week. I manage that sort of workload by putting it on top of my diary. This is the key to success-you can’t follow a career in any field without being well-organized. List what you believe you can achieve. Trust yourself, write down your goals for the day, however small they are, and you’ll be a step closer to achieving them.”

 Kirsten Best

 Poet & Writer

“When things are getting hard, a voice inside my head tells me that I can’t achieve something. Then, there are other distractions, such as family or hobbies. The key is to concentrate. When I feel tense, it helps a lot to repeat words such as ‘calm’, ‘peace’ or ‘focus’, either out loud or silently in my mind. It makes me feel more in control and increases my confidence. This is a habit that can become second nature quite easily and is a powerful psychological(心理的) tool”

Passage 1

(09·浙江E篇)

Four people in England back in 1953, stared at Photo 51,It wasn’t much-a picture showing a black X. But three of these people won the Nobel Prize for figuring out what the photo really showed –the shape of DNA The discovery brought fame and fortune to scientists James Watson, Francis Crick, and Maurice Wilkins. The fourth, the one who actually made the picture, was left out.

  Her name was Rosalind Franklin.”She should have been up there,” says historian Mary Bowden.” If her photos hadn’t been there, the others couldn’t have come up with the structure.” One reason Franklin was missing was that she had died of cancer four years before the Nobel decision. But now scholars doubt that Franklin was not only robbed of her life by disease but robbed of credit by her competitors

  At Cambridge University in the 1950s, Watson and Click tried to make models by cutting up shapes of DNA’s parts and then putting them together. In the meantime, at King’s College in London, Franklin and Wilkins shone X-rays at the molecule(分子). The rays produced patterns reflection the shape.

  But Wilkins and Franklin’s relationship was a lot rockier than the celebrated teamwork of Watson and Crick, Wilkins thought Franklin was hired to be his assistant .But the college actually employed her to take over the DNA project.

What she did was produce X-ray pictures that told Watson and Crick that one of their early models was inside out. And she was not shy about saying so. That angered Watson, who attacked her in return, “Mere inspection suggested that she would not easily bend. Clearly she had to to go or be put in her place.”

As Franklin’s competitors, Wilkins, Watson  and Crick had much to gain by cutting her out of the little group of researchers, says historian Pnina Abir-Am. In 1962 at the Nobel Prize awarding ceremony, Wilkins thanked 13 colleagues by name before he mentioned Franklin, Watson wrote his book laughing at her. Crick wrote in 1974 that  “Franklin was only two steps away  from the solution.”

 No, Franklin was the solution. “She contributed more than any other player to solving the structure of  DNA . She must be considered a co-discoverer,” Abir-Am says. This was backed up by Aaron Klug, who worked with Franklin and later won a Nobel Prize himself. Once described as the  “Dark Lady of DNA”, Franklin is finally coming into the light.

57. What is the text mainly about?

  A. The disagreements among DNA researchers.

  B. The unfair treatment of Franklin.

  C. The process of discovering DNA.

  D. The race between two teams of scientists.

35.(黄石)某化学兴趣小组的同学对一瓶久置的熟石灰粉末的组成进行实验探究,请你一起参与他们的探究活动。

[提出问题] 这瓶熟石灰粉末是否已经变质生成了CaCO3

[进行猜想] 猜想一:熟石灰全部变成了CaCO3

      猜想二:熟石灰部分变成了CaCO3

      猜想一:熟石灰没有变质。

[设计实验] 该小组同学对猜想一设计了下列探究方案,请你帮助他们完成下表中相关实验内容。

实验步骤
实验现象
实验结论
①   取样,加适量水,搅拌,过滤
②   取少量滤液于试管中,滴入酚酞试液
③   取少量滤渣于试管中,加入盐酸
 
②________________。
③________________。
 
猜想一成立

[反思与应用] ①要证明猜想二成立,可参照上述实验方案进行探究,在步骤②中产生的实验现象是_____________________。

②熟石灰变质是由于_____________________的缘故。在初中化学我们所学过的物质中还有_____________________(举一例)等具有这样的性质,因此像熟石灰这类物质在实验室应_____________________保存。

③称取1.0g上述熟石灰样品,加适量水使之充分溶解,搅拌过滤后,往滤液中滴入酚酞试液,同时加入溶质质量分数为10%的盐酸至溶液刚好变为无色,消耗盐酸溶液7.3g。求样品中Ca(OH)2的质量分数(写出计算过程)。

[设计实验]②滤液不变色  ③滤渣溶解,有气泡产生

[反思与应用] ①溶液变红  ②与中的CO2反应  NaOH  密封

③解:设样品中含的质量为x

Ca(OH)2+2HCl=CaCl2+2H2O

74    73

x     7.3g×10%

74/x=73/7.3g×10%  

x=0.74g

则样品中Ca(OH)2的质量分数为Ca(OH)2%=0.74/1×100%=74%

答:样品中Ca(OH)2的质量分数为74%。

34.(孝感)三聚氰胺(化学式为C3H6N6)是一种白色结晶粉末,无气味,低毒,对人体有着某种危害作用,在有机化工中用途广泛;因其含氮量高,而俗称“蛋白精”。2008年卫生部查明,不法分子为了提高婴幼儿奶粉中的蛋白质含量而加入三聚氰胺,导致发生多起婴幼儿泌尿系统结石病例,在社会上引起了广泛关注。某化学兴趣小组的同学欲探究三聚氰胺的制取原理: [查阅资料] (1)目前,化工企业常用尿素合成法制取三聚氰胺。即以尿素[化学式:CO(NH2)2]为反应物,硅胶为催化剂,在380℃至400℃的温度下,沸腾反应、冷凝得到三聚氰胺,同时产生两种无色气体,其中一种气体具有刺激性气味。 (2)NO是无色气体,不溶于水,在空气中能迅速氧化为红色NO2气体。 [提出问题] 反应生成的两种气体是什么? [假设猜想] 根据资料及反应物质判断,生成的两种气体可能是: ①二氧化碳和水蒸气;          ②二氧化碳和氨气; ③二氧化碳和氮气;            ④二氧化碳和二氧化氮; • • • • • • 提出以上猜想的依据是            ; 你认为合理的猜想是(填序号    ,理由是                 [设计实验] 同学们在老师的指导下,设计下图所示实验摸拟制取三聚氰胺,并验证猜想。

A装置的作用是使生成的三聚氰胺迅速凝华而与气体分离。 [实验现象和分析] (1)实验观察到B中棉花变红,则证明生成了     ,同时看到D中________________现象,说明还生成了二氧化碳。 (2)C中浓硫酸的作用是    。 [实验结论] 根据资料和实验现象分析可知,用尿素分解制取三聚氰胺的化学方程式为      ___________________________________________________________。 [假设猜想]反应前后元素种类不变,② 只有②中气体符合无色、有刺激性气味(每空1分)

[实验现象和分析](1)氨气(或NH3) 澄清石灰水变浑浊;(2)吸收氨气(每空1分)

[实验结论]6CO(NH2)2C3H6O6+6NH3↑+3CO2

 0  411686  411694  411700  411704  411710  411712  411716  411722  411724  411730  411736  411740  411742  411746  411752  411754  411760  411764  411766  411770  411772  411776  411778  411780  411781  411782  411784  411785  411786  411788  411790  411794  411796  411800  411802  411806  411812  411814  411820  411824  411826  411830  411836  411842  411844  411850  411854  411856  411862  411866  411872  411880  447090 

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网