A．                          B．7                            C．9                            D．1

7．直线与抛物线相切，则m的值为

C．                                                D．

   A．                                  B．

6．不等式的解集为

C．                                           D．

   A．                                          B．           

5．已知椭圆和双曲线有公共焦点，那么双曲线的渐近线方程是

C．或                                      D．

   A．或                                     B．