下列各项,不支持艾滋病诊断的是()。 A.反复出现带状疱疹 B.间歇或持续发热1

题型:单项选择题

问题:

下列各项,不支持艾滋病诊断的是()。

A.反复出现带状疱疹

B.间歇或持续发热1个月以上

C.头痛,蛛网膜下腔出血

D.口咽念珠菌感染

E.反复出现慢性播散性单纯疱疹感染

考点:全科医学住院医师传染科传染科题库
题型:单项选择题

(9分)假设宇宙中存在一些离其它恒星较远的、由质量相等的四颗星组成的四星系统,设其它星体对它们的引力作用可忽略。已知稳定的四星系统存在两种基本构成形式,一种形式是三颗星位于等边三角形的三个顶点上,第四颗位于其中心,顶点上的三颗星沿外接于等边三角形的圆形轨道运行;另一种形式是四颗星位于正方形的四个顶点上,围绕正方形的中心做圆轨道运行。设所有星体的质量均相等,等边三角形边长和正方形边长相等,试求出这两种情况下四星系统的运动周期T1和T2之比。

题型:单项选择题

In an ideal world, people would not test medicines on animals. Such experiments are stressful and sometimes painful for animals, and expensive and time–consuming for people. Yet animal experimentation is still needed to help bridge vast gaps in medical knowledge. That is why there are some 50 to 100 million animals used in research around the world each year.

Europe, on the whole, has the world’s most restrictive laws on animal experiments. Even so, its scientists use some 12 million animals a year, most of them mice and rats, for medical research. Official statistics show that just 1.1 million animals are used in research in America each year. But that is misleading. The American authorities do not think mice and rats are worth counting and, as these are the most common laboratory animals, the true figure is much higher. Japan and China have even less comprehensive data than America.

Now Europe is reforming the rules governing animal experiments by restricting the number of animals used in labs. Alternatives to animal testing, such as using human tissue or computer models, are now strongly recommended. In addition, sharing all research results freely should help to reduce the number of animals for scientific use. At present, scientists often share only the results of successful experiments. If their findings do not fit the hypothesis being tested, the work never sees the light of day. This practice means wasting time, money, and animals’ lives in endlessly repeating the failed experiments.

Animal experimentation has taught humanity a great deal and saved countless lives. It needs to continue, even if that means animals sometimes suffer. Europe’s new measures should eventually both reduce the number of animals used in experiments and improve the way in which scientific research is conducted.

小题1:What is the main idea of this passage?

A.The success of animal experiments should be ensured.

B.A ban on the use of animals in the lab should be enforced.

C.Greater efforts need to be taken to reduce the number of lab animals.

D.Scientists should be required to share their research results with each other.小题2:Which of the following statements is true about animals used in the lab?

A.America uses only about 1.1 million lab animals per year.

B.Europe does not use mice and rats as lab animals at all.

C.Britain does not use as many lab animals as China does.

D.Japan has less comprehensive data on the number of lab animals used each year.小题3:Which of the following is mentioned as an alternative to replace animal experiments?

A.Statistical studies.

B.Computer models.

C.DNA planted in animals.

D.Tissue from dead animals.小题4:What usually happens to unsuccessful animal experiments?

A.They are not revealed to the public.

B.They are made into teaching materials.

C.They are collected for future publication.

D.They are not removed from the research topic list.

题型:单项选择题

属于定性预测的方法:有()。

A.专家会议法

B.特尔菲法

C.指数平滑法

D.投入产出模型

E.类推预测法

题型:单项选择题

[问题2]对于表2-2、表2-3所示的“职工”和“部门”关系,请指出下列各行是否可以插入,为什么

题型:单项选择题

食品工厂常见的阀门有哪些(至少5个)?

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