应用题某设备，估值5500万元，使用寿命尚有6年，其他数据如下表（单位：万元），试计算其经济寿命（不考虑资金的时间价值）。

应用题已知某企业的短期总成本函数是STC（Q）=0.04Q3-0.8Q2+10Q+5，求最小的平均可变成本值。（4分）

应用题已知W 国的宏观经济可以用下列一组方程式来描述： 消费函数：C=120+0.8Y············（1） 投资函数：I=50-200r··············（2） 收入恒等式：Y=C+I···············（3） 货币需求函数：L=（0.5-500r）P····（4） 其中，C为消费，Y 国民收入，I为投资，r为利率，P为价格总水平，L为货币需求。 （1）如果在2003 年，W 国的价格总水平为2，货币供应量为500。试写出W 国的IS曲线和LM 曲线方程。 （2）写出W 国的总需求函数。 （3）W国的宏观经济均衡时国民收入和利率分别是多少？

应用题已知消费者对某种商品的需求函数为Q=100-2p，写出相应的总收益函数和边际收益函数。在什么价格水平上，需求价格弹性系数为1？

应用题请在IS-LM成本分析框架范围内分析古典主义的极端情况。

应用题如果消费需求C＝100＋0.8Yd（Yd为可支配收入），投资需求I＝150－6r，税收T＝50，政府支出G＝40；如果经济的名义货币供给为150，货币需求为0.2y－4r，分别求出在P＝1和P＝1.2时均衡的收入和利率水平。

应用题若某种商品征收税收之前，供给和需求方程分别为Qs=2P Qd=300-P假如对买者征收税收T，新的需求方程为：Qd=300-（P+T） 　　试求：（1）税收收入函数S，并画图说明税收收入与税收规模（T）之间的关系。（3分） 　　（2）当税收收入为最高值时，无谓损失为多少？（3分） 　　（注：该商品价格单位为元，商品数量单位为公斤）

应用题某家庭欲在5年后购买某设施需要50万元。如过每年末存入银行6.6万元，银行年利率为10%，问该家庭（1）5年后能否用银行的本利和购买该设施（7分）？（2）每年末至少 应存入多少钱，就能在5年后购买该设施（8分）？（假定5年之内该设施的市场价格不变）

单选题In the USA, 85% of the population over the age if 21 approve of the death penalty. In the many states whcih still have the death penalty, some use the electric chair, which can take up to 20 minutes to kill, while others use gas or lethal injection. The first of these was the case of Ruth Ellis who was hanged for shooting her lover in what was generally regarded as a crime of passion. The second was hanged for murders which, it was later proved, had been committed by someone else. The pro-hanging lobby uses four main arguments to support its call for the reintroduction of capital punishment. First there is the deterrence theory, which argues that potential murderers would think twice before committing the act if they knew that they might die if they were caught. The armed bank robber might, likewise, go back to being unarmed. The other two arguments are more suspect. The idea of retribution demands that criminals should get what they deserve: if a murderer intentionally set out to commit a crime, he should accept the consequences. Retribution, which is just another word for revenge, is supported by the religious doctrine of an eye for an eye and a tooth for a tooth. The arguments against the death penalty are largely humanitarian. But there are also statistical reasons for opposing it: the deterrence figures do not add up. In Britain,1903 was the the record year for executions and yet in 1904 the number of murders actually rose. There was a similar occurrence in 1946 and 1947. If the deterrence theory were correct, the rate should have fallen. The other reasons to oppose the death penalty are largely a mather of individual conscience and belief. One is that murder is murder and that the state has no more right to take a lifer than the individual. The other is that Christianity advises forgiveness, not revenge.

单选题中国多所高校在多伦多、纽约、波士顿、旧金山召开了4场人才招聘会，针对出席招聘会的中国留学生做了问卷调查。调查显示：67%的人希望回国工作，33%的人会认真考虑回国的选择。可见，在美国工作对中国留学生已失去吸引力，人心思归已蔚然成风。 以下哪一项陈述准确指出了上述论证的缺陷?

单选题风险规避者的无差异曲线( )。

单选题设X 1 ，X 2 ，X 3 服从区间[0，2]上的均匀分布，则E(2X 1 -X 2 +3X 3 )=______．

单选题所得税的增加将引起充分就业的预算盈余( )。

单选题For years Internet merchants have poured millions of dollars into new technologies to make their sites easier to use. So why aren't online customers happier? Customer satisfaction levels have remained almost flat through the last several years. The problem, according to Larry Freed, chief executive of a consulting and research firm called ForeSee Results, is not so much that consumers have ignored the many improvements made in recent years. Rather, he said, they still expect more from Internet shopping than it has delivered. "If we walk into a local store, we don't expect that experience to be better than it was a couple years ago," Mr. Freed said. "But we expect sites to be better. The bar goes up every year. " In ForeSee's latest survey, released last month, just five e-commerce sites registered scores higher than 80 out of 100, and no site scored higher than 85. It was much the same story a year ago, when just five scored higher than 80, with no site surpassing 85. "Scores have inched up over time for the best e-commerce companies, but the overall numbers haven't moved drastically," Mr. Freed said. "At the same time though, if you don't do anything you see your scores drop steadily. " That dynamic has been a challenge for online merchants and investors, who a decade ago envisioned Internet stores as relatively inexpensive (and therefore extremely profitable) operations. Now some observers predict a future where online retailers will essentially adopt something like the QVC model, with sales staff pitching the site's merchandise with polished video presentations, produced in a high-tech television studio. QVC.com is evolving in that direction. The Web site, which sold more than $1 billion in merchandise in 2006, has for the last five years let visitors watch a live feed of the network's broadcast. But in recent months, QVC.com has also given visitors the chance to watch archives of entire shows, and in the coming months visitors will be able to find more video segments from recent shows, featuring individual products that remain in stock. Bob Myers, senior vice president of QVC.com, said the Web site's video salesmanship is especially effective when combined with detailed product information, customer reviews and multiple photographs. About eight months ago, for instance, a customer said that she could not determine the size of a handbag from the photographs on the site because she could not tell the height of the model who was holding it. Within two weeks the site tested and introduced a new system, showing the bags with women of three different heights. The results were immediate: women who saw the new photographs bought the bags at least 10 percent more frequently than those who had not. Still, Mr. Myers said, video is a critically important element to sales. "E-commerce started with television commerce," he said. "The sites who engage and entertain customers will be winning here in the near future. " Such a prospect is not necessarily daunting to other e-commerce executives. Gordon Magee, head of Internet marketing for Drs. Foster & Smith, based in a Rhinelander, Wis. , said a transition to video "will be seamless for us. " The company, Mr. Magee said, has in recent weeks discussed putting some of its product on video "so customers could see a 360-degree view they don't have to manipulate themselves. /

单选题设F 1 (x)，F 2 (x)为两个分布函数，其相应的概率密度f 1 (x)，f 2 (x)是连续函数．则必为概率密度的是______．

单选题若A，B均为n阶方阵，则正确的是______．

单选题日本市场经济模式是一种（ ）市场经济模式。