设255bm，且1a1b2，则mA．10B．10C．20D．-优题课

设 $2^{5} = 5^{b} = m$ ，且 $\frac{1}{a} + \frac{1}{b} = 2$ ，则 $m =$

A．

\sqrt{10}

B．

C．

D．

100

科目数学题型选择题难度中等

知识点：原根与指数

Suppose the least distance fron poinrs of the xurve(曲线)to the y-axis is then the velue of a is

设为椭圆上一点，且,，其中为椭圆的两个焦点，则椭圆的离心率e的值等于

A．	B．
C．	D．

当x.yi满足条件时，变量U=的取值范围是

等差数列中有两项和，满足、，则该数列前mk项之和是

Ahyperbola(双曲线)wjthvertices(顶点)（-2，5）and(-2,-3),has an asynptote(渐近线)that passes the point(2.5) Then an equarionk of the hyperbola is

A．	B．
C．	D．