— Can you come to a party on Saturday, Peter?
— Oh, ______I'm already going out, I'm afraid.
A:what a pity!
B:don't ask!
C:how come?
D:so what?
如图,圆的四条半径分别是OA,OB,OC,OD,其中点O,A,B在同一条直线上,∠AOD=90°,∠AOC=3∠BOC,那么圆被四条半径分成的四个扇形的面积的比是( )
A.氢氧化钠 B.碳酸钙
C.硝酸铵 D.____