A．                B．                        C．            D．

7．若关于的不等式组有解，则实数的取值范围是

C．                               D．

A．                                    B．

6．下列计算错误的是

A．                B．                    C．                   D．

5．化简的结果是

A．70°                     B．80°                        C．90°                        D．100°

4．如下图，已知直线AB∥CD，∠C＝115°，∠A＝25°，则∠E＝

C．                                      D．