单选题已知a 1 ，a 2 ，a 3 ，a 4 ，a 5 是满足条件a 1 +a 2 +a 3 +a 4 +a 5 =-7的不同整数，b是关于x的一元五次方程(x-a 1 )(x-a 2 )(x-a 3 )(x-a 4 )(x-a 5 )=1773的整数根，则b的值为______．

单选题已知y=y1-y2，且y1与成反比例，y2与成正比例．当x=0时，y=-3，又当x=1时，y=1，那么y关于x的函数是______．A．B．C．D．E．

单选题在正三棱柱ABC—A1B1C1中，若AB=BB1，则AB1与C1B所成的角的大小为{{U}}{{/U}}。A.60°B.90°C.105°D.75°

单选题=______。A．ln11B．11C．-ln11D．

单选题不等式的解集是()。

单选题设函数，则f'(1)=()．

单选题 Resistance to the 1954 United States Supreme Court decision terminating segregation placed the schools in the middle of a bitter and sometimes violent dispute. By 1965, when a measure of genuine integration had become a reality in many school districts, tile schools again found themselves in the eye of a stormy controversy. This time the question was not which children were going to what schools but what kind of education society should provide for the students. The goal of high academic performance, which had been revived by criticisms and reforms of the 1950s and early 1960s, began to be challenged by demands for more liberal and free schooling. Many university and some high-school students from all ethnic groups and classes had been growing more and more frustrated--some of them desperately so--over what they felt was a cruel and senseless war in Vietnam and a cruel, discriminatory, competitive, loveless society at home. They demanded curriculum reform, improved teaching methods, and greater stress and action on such problems as overpopulation, pollution, international strife, deadly weaponry, and discrimination. Pressure for reform came not only from students but also from many educators. While students and educators alike spoke of the greater need for what was taught, opinions as to what was relevant varied greatly. The blacks wanted new textbooks in which their people were recognized and fairly represented, and some of them wanted courses in black studies. They, and many white educators, also objected to culturally biased intelligence and aptitude tests and to academic college entrance standards and examinations. Such tests, they said, did not take into account the diverse backgrounds of students who belonged to ethnic minorities and whose culture was therefore different from that of the white middle-class student. Whites and blacks alike also wanted a curriculum that touched more closely on contemporary social problems and teaching methods that recognized their existence as individual human beings rather than as faceless robots competing for grades. Alarmed by the helplessness and hopelessness of the urban ghetto schools, educators began to insist on curricula and teaching methods flexible enough to provide for differences in students' social and ethnic backgrounds. Moreover, for educational reformers the urban ghetto school became a symbol of a general failure of American education to accomplish the goal of individual development. Also reminiscent of those decades were the child-centered schools that sprang up in the later 1960s as alternatives to and examples for tile traditional schools. The clash between the academically and the humanistically oriented schools of thought, therefore, was in many ways one more encounter in the continuing battle between conservative and liberals.

单选题在等差数列{an}中，a3=2，a11=6，数列{bn}是等比数列，若b2=a3，，那么满足最大的n的值为{{U}}{{/U}}。A.2B.3C.4D.5

单选题某洗衣机生产厂家，为了检测其产品无故障的启动次数，从生产的一批洗衣机中任意抽取了5台，如果测得的每台无故障启动次数分别为11300，11000，10700，10000，9500，那么这批洗衣机的平均无故障启动次数大约为______．

单选题已知点A(1，-2)，B(m，2)，且线段AB的垂直平分线的方程是x+2y-2=0，则实数m的值是______

单选题已知数列1×3，2×4，3×5，…，则255是它的______。 A．第14项 B．第15项 C．第16项 D．第18项

单选题 on April 20,2000, in Accra, Ghana, the leaders of six West African countries declared their intention to proceed to monetary union among the non CFA franc countries of the region by January 2003, as first step toward a wider monetary union including all the ECOWAS countries in 2004. The six countries{{U}} 56 {{/U}}themselves to reducing central bank financing of budget deficits{{U}} 57 {{/U}}10 percent of the previous years government{{U}} 58 {{/U}};reducing budget deficits to 4 percent of the second phase by 2003 ;creating a Convergence Council to help{{U}} 59 {{/U}}macroeconomic policies; and{{U}} 60 {{/U}}up a common central bank. Their declaration{{U}} 61 {{/U}}that, "Member States{{U}} 62 {{/U}}the need{{U}} 63 {{/U}}strong political commitment and{{U}} 64 {{/U}}to{{U}} 65 {{/U}}all such national policies{{U}} 66 {{/U}}would facilitate the regional monetary integration process. " The goal of a monetary union in ECOWAS has long been an objective of the organization, going back to its formation in 1975, and is intended to{{U}} 67 {{/U}}broader integration process that would include enhanced regional trade and{{U}} 68 {{/U}}institutions. In the colonial period, currency boards linked sets of countries in the region.{{U}} 69 {{/U}}independence,{{U}} 70 {{/U}},these currency boards were{{U}} 71 {{/U}},with the{{U}} 72 {{/U}}of the CFA franc zone, which included the Francophone countries of the region. Although there have been attempts to advance the agenda of ECOWAS monetary cooperation, political problems and other economic priorities in several of the region's countries have to{{U}} 73 {{/U}}inhibited progress. Although some problems remain, the recent initiative has been bolstered by the election in 1999 of a democratic government and a leader who is committed to regional{{U}} 74 {{/U}}in Nigeria, the largest economy of the region, raising hopes that the long delayed project can be{{U}} 75 {{/U}}.

单选题设函数，则=()．

单选题如果(3a+3b+)(3a+3b-1)=80，那么a+b的值为______A．B．C．3D．-3E．±3