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(本题12分)如图,两个同样大小的等边△ABC和△ACD,边长为a,它们拼成一个菱形ABCD,另一个足够大的等边△AEF绕点A旋转,AE与BC相交于点M,AF与CD相交于点N。

【小题1】(1)证明:∠DAN=∠CAM;
【小题2】(2)求四边形AMCN的面积;
【小题3】(3)探索△AMN何时面积最小,并写出这个最小面积的值.

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二次根式有意义时,的取值范围是(   ).
A.B.C.D.

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方程的根是(   ).
A.="2" B.C.D.

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一只小鸟自由自在地在空中飞行,然后随意落在如图所示的某个方格中(每个方格除颜色外完全一样),那么小鸟停在黑色方格中的概率是(   ).
A.B.C.D.

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如图,梯形ABCD中,对角线AC与BD交于点O,则图中面积相等的三角形有(   ).
A.3对B.2对C.1对D.4对

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US college students are burdened, with credit card (信用卡)debt, according to a study published Tuesday, and the problem can be serious-ranging from more drop-outs, to future employment problems and even self-murder. The study, by Georgetown University sociologist (社会学家) Robert Manning, blamed credit card issuers for actively targeting students and colleges for allowing them to do so. "The unrestricted selling of credit cards in universities or colleges is so aggressive that it now forms a greater threat than alcohol or sexual diseases," Manning told a news conference in Washington. "If we do not quickly deal with this serious problem, the matter will continue to get worse, with social consequences far more tragic (悲剧的) than mere dollars and cents. "
Based on hundreds of face-to-face interviews and surveys with students, Manning concluded both the number with credit card debt and their indebtedness had been "underreported" in previous studies-which failed to reflect the "survival strategies" many used to deal with their debts. These included the use of federal student loans to pay off credit cards, effectively shifting the debt, appealing to parents for loans, reducing course work hours to increase time at paid jobs, or even dropping out altogether to work full time.
"Official drop-out rates include growing numbers of students who are unable to cope with the stress of their debts and / or part time jobs for servicing their credit cards, " the study said. "Students credit card debts are examined during the employment process and may be an important factor in evaluating future employees," it noted. O’Donnell and Manning agreed students should bear some responsibility for reckless use of credit, but said credit card companies also had to be held responsible for making it so easy for them to get into debt. Manning said one of the most troublesome aspects of the student credit card issue was "the seduction (诱惑) of college and university officials by the credit card industry".
【小题1】Sociologist Robert Manning's study shows that     .
A.the number of American college students using credit cards on campus is increasing
B.more and more American college students meet with credit card debt problems
C.more and more American colleges encourage students to use credit cards to make profits
D.credit card issuers will run into debt for encouraging college students to use credit cards
【小题2】The author's feeling towards college students with credit card debts is __.
A.discouraged and negativeB.pitiful and critical
C.indifferent and disapprovingD.negative and doubtful
【小题3】The author implies all of following should be responsible for this problem EXCEPT      .
A.credit card issuers B.college authorities
C.parents of the studentsD.students themselves
【小题4】The word "reckless" in Paragraph 3 can be replaced by        .
A.inconsiderateB.frequent C.carefulD.regular

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如图,△ADE∽△ABC,若AD=1,BD=2,则△ADE与△ABC的相似比是(   ).
A.1:2B.1:3C.2:3D.3:2

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如图,数轴所示两点表示两数,则下列比较的大小正确的是(   ).
A.>B.<
C.=D.无法比较

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抛物线的对称轴是直线=1,且经过点P(3,0),则的值为(   ).
A.0B.-lC.1D.2

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计算:___________.

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