题目

— Will Mr Wang offer us a hand? — He ____ be glad to. He never refused our request.       A. can                B. must              C. may                       D. should 答案：B5、若菱形的周长是40，两邻边所夹的锐角为30°，则菱形的面积为（　　）A、20B、30C、40D、50