单选题设f(x)具有任意阶导数，且f'(x)=[f(x)]2，则f"'(x)=( ) A．3[f(x)]4 B．4[f(x)]4 C．6[f(x)]4 D．12[f(x)]4

单选题某检察机关在查处一贪污案时，找证人王某了解情况。谈话结束时，侦查人员顺便问：“你自己有无问题需要说清楚?”王某一时语塞，侦查人员见状便予以政策教育，王某遂交代了自己受贿5万元的犯罪事实。根据刑法规定，对王某受贿罪量刑时应考虑哪种情节?( ) A．自首情节 B．立功情节 C．揭发他人情节 D．认罪服法情节

单选题What do you think of American health care system? Most people would be (1) by the high quality of medicine (2) to most Americans. There is a lot of specialization, a great deal of (3) to the individual, a (4) amount of advanced technical equipment, and (5) effort not to make mistakes because of the financial risk which doctors and hospitals must (6) in the courts if they (7) things badly. But the Americans are in a mess. To the problem is the way in (8) health care is organized and (9) . (10) to pubic belief it is not just a free competition system. To the private system has been joined a large public system, because private care was simply not (11) the less fortunate and the elderly. But even with this huge public part of the system, (12) this year will eat up 84.5 billion dollars—more than 10 percent of the U. S. Budget—a large number of Americans are left (13) . These include about half the 11 million unemployed and those who fail to meet the strict limits (14) income fixed by a government trying to make savings where it can. The basic problem, however, is that there is no central control (15) the health system. There is no (16) to what doctors and hospitals charge for their services, other than what the public is able to pay. The number of doctors has shot up and prices have climbed. When faced with toothache, a sick child, or a heart attack, all the unfortunate persons concerned can do is to pay (17) . Two thirds of the population are (18) by medical insurance. Doctors charge as much as they want (19) that the insurance company will pay the bill. The rising cost of medicine in the U. S. A. is among the most worrying problems facing the country. In 1981 the country's health bill climbed 15.9 percent—about twice as fast as prices (20) general.

单选题曲线x 2 +y 2 =2x在点(1，1)处的法线方程为______

单选题三直线ax+2y+8=0，4x+3y=10，2x-y=10相交于一点，则a=______。 A．-2 B．-1 C．0 D．1

单选题设F(x)是f(x)的一个原函数，则∫e-xf(e-x)dx等于______ A.F(e-x)+C B.-F(e-x)+C C.F(ex)+C D.-F(ex)+C

单选题设级数收敛，则级数______．

单选题设某种商品的需求量为Q，价格为P，且已知该商品的边际收益函数为，则该商品的需求函数Q=Q(P)的表达式为

单选题 特解为： A、； B、； C、； D、。

单选题函数的最小值是______．

单选题设事件A，B，C两两独立，则A，B，C相互独立的充分必要条件是( )

单选题下列各组角中，可以作为向量的方向角的是______A．B．C．D．

单选题曲线与x轴所围成的面积为______。

单选题某班学生去植树，全班人数的去挖树坑，余下人数的运树苗，最后余下的4名同学负责供应开水，则这个班共有学生()人．

单选题设A是4阶方阵，则下列线性方程组是同解方程组的是______

单选题一袋核桃有365个，分为若干堆，有的堆有30个，有的有28个，有的有31个．这些核桃分为了( )．

单选题某商品打九折会使销售增加20％，则这一折扣会使销售额增加的百分比是( )．

单选题已知直线ax—by+3=0(a＞0，b＞0)过圆x2+4x+y2一2y+1=0的圆心，则ab的最大值为()．

单选题若不等式的解集是(0，4]，则a的取值范围是______．