题目

— Did Alice enjoy the concert held in Grand Theater yesterday?    — Yes, she did. She _____ such an excellent concert for a long time. A. didn’t take part in                  B. wouldn’t take part in C. hasn’t been in                     D. hadn’t been in  答案：D 解析: 略已知a、b是实数，则“a＞1，b＞1”是“a+b＞2且ab＞1”的（　　） A、充分而不必要条件B、必要而不充分条件C、充分且必要条件D、既不充分也不必要条