A:pleasant
B:anxious
C:hopeful
D:disappointing
—You went out and enjoyed yourself when you________.
—I'm sorry,Mum. I'll finish my homework tonight.
已知函数:fx=x2+bx+c,其中:0≤b≤4,0≤c≤4,记函数fx满足条件:f2≤12f-1≤3的事件为A,则事件A发生的概率为( )