题目

下列运算正确的是                       (    ) A．a2＋a3=a5       B．a2•a3=a6      C．a3÷a2=a      D．(a2)3=a8      答案：答案：Ｃ31、―______. ―I think quite the opposite.       A. She must be quite satisfied with the progress that has been made.       B. If you have any question, don’t hesitate to call me!       C. I wonder if you could come over and help me a while. I just can’t manage it.       D. Nobody knows what he means. He just keeps his mouth closed all the day.