问题 单项选择题

关于血浆渗透压的叙述,下列哪一项是正确的

A.血浆渗透压主要来自血浆蛋白

B.血浆渗透压主要来自血浆中的电解质

C.血浆蛋白减少时血浆渗透压将明显降低

D.血浆渗透压决定了血管内、外水平衡

E.血浆渗透压发生变化时红细胞的脆性发生变化

答案

参考答案:B

解析:
[考点] 血浆的理化特性
[分析] 血浆渗透压约为300mmol/L(即300 mOsm/kg·H2O,约相当于770 kPa),主要来自溶解于其中的晶体物质,特别是电解质,也有一小部分来自血浆蛋白。但血浆蛋白形成的渗透压大约为1.5mOsm/kg·H2O,约相当于3.3kPa(25mmHg),与总渗透压相比,所占的比例很小,故当血浆蛋白减少时,血浆总渗透压不会明显降低。红细胞脆性指红细胞对渗透压的抵抗能力,这种能力的变化是红细胞疾病的表现,而不是血浆渗透压改变形成的。血浆与组织液中晶体物质的浓度几乎相等,它们的晶体渗透压也基本相等。但组织液中的蛋白质很少,由蛋白质形成的胶体渗透压低于血浆的胶体渗透压。由于血浆蛋白一般不能透过血管壁,虽然血浆胶体渗透压在总渗透压中占的比例很小,但对于维持血管内、外的水平衡有重要作用。

阅读理解

New crime prediction software should reduce not only the murder rate, but the rate of other crimes. Developed by Richard Berk, a professor at the University of Pennsylvania, the software has already used in Baltimore and Philadelphia to predict which individuals on probation(缓刑) or parole(假释) are most likely to murder and to be murdered.

“When a person goes on probation or parole he is supervised(监督) by an officer. The question is ‘what level of supervision is appropriate?’” said Berk. It used to be that parole officers used the person’s criminal record, and their judgment to make decisions.

“This research replaces those seat-of-the –pants calculations,” he said.

Technology helps determine level of supervision. On average there is one murder for every 100,000 people. Even among high-risk groups the murder rate is one in 100. Predicting such a rare event is very difficult, but advances in computer technology works.

Years ago, the researchers made a dataset of more than 60,000 various crimes. Using the software they developed, they found some much more likely to commit murder when paroled or probated. They could identify eight future murderers out of 100.

Berk’s software examines roughly two dozen variables(可变因素), from criminal record to geographic location. The type of crimes, and more importantly, the age at which that crime was committed, were two of the most predictive variables.

“People assume that if someone murdered then they will murder in the future,” said Berk. “ What really matters is what that person did as a young individual. Predicting future crimes sounds well. But we aren’t anywhere near being able to do that.”

“Berk’s scientific answer leaves policymakers with difficult questions. By labeling one group of people as high risk, and supervise them closely, there should be fewer murders, which the potential victims should be happy about. It also means that those high-risk individuals will be supervised more aggressively. For human rights advocates, that means punishing people who, most likely, will not commit a crime in the future,” said Bushway. “It comes down to a question of whether you would rather make these errors or those errors.”

小题1:The underlined words(in Para.3) probably mean___. 

A.calculations based on subjective opinions

B.calculations based on widespread voting

C.calculations made by advanced technology

D.calculations based on serious considering小题2:For 650 people with crime records, how many potential murderers would the software find?

A.6.5.

B.13.

C.52.

D.65.小题3:From Para 7, we can infer that______.

A.the technology developed by Richard Berk will soon be widely used in the US

B.the technology would not be widely accepted in the short term

C.whether a person murders or not largely decided by his upbringing while young

D.if a person murdered when he was fifty, he is sure to murder again while on probation小题4:Bushway’s attitude to the technology put forward by Richard Berk is ____.

A.positive

B.negative

C.objective

D.indifferent小题5:Which would be the best title for the passage?

A.Closely Supervise Potential Murders

B.Measures Taken to Prevent Criminal Behavior

C.Technology Revolutionizes Judges’ Way of Working

D.Software is Developed to Predict Criminal Behavior

问答题 简答题