1.已知集合等于
       (A){1,2,3}          (B){2,3}               (C){1,2}        (D){2}
2.复数等于                                             
       (A)1+                     (B)―1―               (C)1―           (D)―1+
3.等于
       (A)0                        (B)                      (C)               (D)1
4.设函数的图像过点(2,1),其反函数的图像过点(2,8),则a+b等于
       (A)3                        (B)4                        (C)5                 (D)6
5.设直线过点(0,a)其斜率为1,且与圆x2+y2=2相切,则a的值为    
       (A)±4                    (B)               (C)±2              (D)
6.“α、β、成等差数列”的“等式sin(α+ )=sin2β成立”的是
       (A)充分而不必要条件                                 (B)必要而不充分条件