A．0                    B．                   C．                  D．1

    （文）等差数列{a_n}中，S₁₀=120，那么a₂+a₉的值是                                           (    )

       A．12                      B．16                      C．24                     D．48

8．（理）数列{a_n}中a₃=2，a₇=1，如果数列{}是等差数列，那么a₁₁=           (　　)

C．y=－(x≥)                D．y= (x≥)

A．y=－(x≥0)                           B．y=(x≥0)

7．函数的y=(x≤－1)反函数是                                                                 (    )

       A．                  B．                    C．                  D．

6．已知双曲线(a>0)的右焦点与抛物线y²=16x的焦点重合，则该双曲线的离心率等于                                                                                                                    (    )

C．y=2sin(2x+)        D．y=2sin(2x－)

A．y=2sin(4x+)         B．y=2sin(4x－)