题目

 — What about ______ bike? — Do you think it all right to buy him that bike as ______ birthday gift?   A. a; a                    B. the; a                        C. a; /                           D. the; / 答案：B已知关于x的方程x2-（k+1）x+k 2+1=0（1）若方程有两个实数根，求k的取值范围．（2）是否存在k值，使方程的两个实根互为倒数？若存在求出k的值；若不存在，说明理由．