单选题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.
单选题生活应该是一系列冒险，它很有乐趣，偶尔让人感到兴奋，有时却好像是通向不可预知未来的痛苦旅程。当你试图以一种创造性的方式生活时，即使身处沙漠中，也会遇到灵感之井、妙想之泉，但它们不是能事先拥有的。
下面哪一个选项所强调的意思与题干的主旨相同?
单选题下列各项中，不会对投资项目的内部收益率指标产生影响的因素是（ ）
单选题某人对x商品的恩格尔曲线的斜率保持在1的水平不变，则其在(12，8)点的收入弹性为( )。
单选题某个会议与会人员的情况如下：
(1)3人是由基层提升上来的；
(2)4人是北方人；
(3)2人是黑龙江人；
(4)5人拥有博士学位；
(5)黑龙江人没有博士学位；
(6)上述情况包含与会的所有人员。
那么，与会人员的人数是：
单选题假设某个小国的总量生产函数为Y=AK
0.3
L
0.7
。当该国的全要素生产率增加一倍后，该国的总产出将( )。
单选题消费者储蓄增多而消费支出减少，则( )
单选题蛛网模型以______假定为前提。( )
单选题平均而言，今天受过教育的人的读书时间明显少于50年前受过教育的人的读书时间。但是，现在每年销售的书册数却比50年前增加了很多。
以下大多项陈述都有助于解释上述现象，除了哪一项?
单选题完全竞争市场的厂商短期供给曲线是（ ）
单选题假设消费者的效用函数为u(x,y)=ln(x
0.5
+y)，同时消费者所面临的商品空间由商品x和商品y构成。在二维的商品空间中．如果我们以y的数量为纵轴，以x的数量为横轴，那么消费者在此商品空间中的无差异曲线的斜率为( )
单选题如果y=k
1/2
，s=0．4，折旧率=20％，稳态人均资本存量为( )。
单选题由于在乐业天坑中最大的天坑——大石围底部的原始森林中发现了与恐龙同时代的植物桫椤，有人据此推测，大石围应形成于恐龙时代，即6500万年前。
下列各项如果为真，哪一项最能反驳上述推测?
单选题在从原点出发的直线(射线)与TC曲线的切点上，AC( )
单选题2009年，某学院首次举行举重比赛，在此之后，每年举行一次，直至2015年。在这短短的几年中，有四个系得过冠军：中文系、历史系、化学系和数学系。比赛结果如下：
(1)在同一年内没有并列冠军队；
(2)数学系是唯一连续几年获胜的运动队；
(3)中文系既没有在2009年获胜，也没有在2015年获胜，化学系也是同样的情况；
(4)历史系在逢偶数的年份中都没有获胜。
如果数学系在2009年和2015年的比赛中均获胜，那么下列哪个判断必然是正确的?
单选题资本主义生产方式的本质特征是（ ）。
单选题设随机变量X和Y同分布，概率密度为，且，则a的值为______．A．B．C．D．
单选题若函数，则f"(x)在点x=0处______．
单选题由于量子理论的结论违反直观，有些科学家对这一理论持不同看法。尽管他们试图严格地表明量子理论的断言是不精确的(试图严格地证伪它)，但是发现，其误差在通常可接受的统计范围之内。量子理论的这些结果不同于与它相竞争的理论的结果，这表明接受量子理论是合理的。
以下哪一项原则最有助于表明上述推理的合理性?
单选题某设备的原始价值为8000元，初始运行费用为400元，每年低劣化增加值为320元，残值为0，则该设备的最优更新期（经济寿命）约为（ ）