物体做竖直上抛运动到最高点时,下列说法正确的是() A.具有向上的速度和向上的加速度

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问题:

物体做竖直上抛运动到最高点时,下列说法正确的是()

A.具有向上的速度和向上的加速度

B.速度为零,加速度向下

C.合力为零

D.物体平衡状态

考点:高中物理竖直上抛运动竖直上抛运动题库
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有关肾性脑病发病机制假说哪项

不对

A.毒素积蓄
B.脑代谢障碍
C.电解质代谢障碍
D.神经递质代谢障碍
E.慢性应激

题型:单项选择题

初级群体和次级群体的区分标准是

A.成员对群体的心理归属

B.成员的互动关系特征

C.群体的关系结构和组织功能

D.群体的规模

题型:单项选择题

A pair of dice, rolled again and again, will eventually produce two sixes. Similarly, the virus that causes influenza is constantly changing at random and, one day, will mutate in a way that will enable it to infect billions of people, and to kill millions. Many experts now believe a global outbreak of pandemic flu is overdue, and that the next one could be as bad as the one in 1918, which killed somewhere between 25m and 50m people. Today however, advances in medicine offer real hope that another such outbreak can be contained-if governments start preparing now.

New research published this week suggests that a relatively small stockpile of an antiviral drug-as little as 3m doses--could be enough to limit sharply a flu pandemic if the drugs were deployed quickly to people in the area surrounding the initial outbreak. The drug’s manufacturer, Roche, is talking to the World Health Organisation about donating such a stockpile.

This is good news. But much more needs to be done, especially with a nasty strain of avian flu spreading in Asia which could mutate into a threat to humans. Since the SARS outbreak in 2003 a few countries have developed plans in preparation for similar episodes. But progress has been shamefully patchy, and there is still far too little international coordination.

A global stockpile of drugs alone would not be much use without an adequate system of surveillance to identify early cases and a way of delivering treatment quickly, If an outbreak occurred in a border region, for example, a swift response would most likely depend on prior agreements between different countries about quarantine and containment.

Reaching such agreements is rarely easy, but that makes the task all the more urgent, Rich countries tend to be better prepared than poor ones, but this should be no consolation to them. Flu does not respect borders. It is in everyone’s interest to make sure that developing countries, especially in Asia, are also well prepared. Many may bridle at interference from outside. But if richer nations were willing to donate anti-viral drugs and guarantee a supply of any vaccine that becomes available, poorer nations might be willing to reach agreements over surveillance and preparedness.

Simply sorting out a few details now will have lives (and recriminations) later. Will there be enough ventilators, makes and drugs Where will people be treated if the hospitals overflow Will food be delivered as normal Too many countries have no answers to these questions.

According to the text, which of the followings is not readily made ()

A. publications of new research with respect to the supply of the interference from outside

B. construction of an adequate system of surveillance of early influenza cases

C.availability of anti-viral drugs and any vaccine in underdeveloped nations

D. contracts between various nations concerning quarantine and containment

题型:单项选择题

早产儿治疗用氧的目的是维持()

A.PaO2为50~60mmHg,TcSO2在90%~95%

B.PaO2为50~80mmHg,TcSO2在90%~95%

C.PaO2为70~80mmHg,TcSO2在95%以上

D.PaO2为50~80mmHg,TcSO2在95%以上

E.PaO2为80mmHg以上,TcSO2在90%~95%

题型:单项选择题

拱形金属可缩性支架架设安全质量要求?

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