题目

如图，顺次连结圆内接矩形各边的中点，得到菱形ABCD，若BD＝6，DF＝4，则菱形ABCD的边长为（    ） A.4             B.3               C.5                 D.7 答案：DIf you want to be a computer programmer, you have to _____. [     ]A. practice basketball B. take piano lessons C. study computer science D. eat healthier food