A:defending
B:to defend
C:having defended
D:defended
定义运算a□b=a(1﹣b),下面给出了关于这种运算的几个结论:
①2□(﹣2)=6;②a□b=b□a;③若a+b=0,则(a□a)+(b□b)=2ab;④若ab=0,则a=0,
其中正确结论的个数( )
Just to satisfy my ____(好奇心), how much did you pay for your car?