题目

He will give me a present that I _____ for a long time. A. expected    B. were expected    C. have been expecting   D. will have been expected 答案：C 解析: 略已知关于x的方程x2+（2k-1）x-2k=0的两个实数根x1、x2满足x1-x2=2，试求k的值．