单选题______ enough time and money, the researchers would have been able to discover more in this field. A. Giving B. To give C. Given D. Being given

单选题积分等于()

单选题已知4维列向量α1，α2，α3线性无关，若βi(i=1，2，3，4)非零且与α1，α2，α3均正交，则秩r(β1，β2，β3，β4)=

单选题若1名女生和3名男生排成一排，则该女生不在两端的不同排法共有（　）

单选题设函数z=sin(xy)，则下列结论正确的是______。A．B．C．D．

单选题下列命题正确的是(A)若导函数有不连续点，则只可能是第二类间断点．(B)若函数f(x)在(a，+∞)内可导，存在，则存在．反之亦然．(C)设函数f(x)有界，且存在，则也必存在．(D)不可能找到两个满足f(0)=g(0)=0的可导函数f(x)及g(x)，使得x=f(x)·g(x)成立．

单选题方程x-|2x+1|=4的根是______．A．x=-5或x=1B．x=5或x=-1C．x=3或D．x=-3或E．不存在

单选题一个长方体表面积是20，所有棱长的和是24，则长方体的体对角线长为______．

单选题等差数列{a n }的前m项和为30，前2m项和为100，则它的前3m项和为______·

单选题下列函数中，在点x=0处不可导的是______。A．y=cosxB．y=arctanxC．D．y=ln(x+1)

单选题有1元、2元、5元、10元、50元的人民币各一张，取其中的一张或几张，能组成______种不同的币值．

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、。