—Whatever the result is, don't be too hard on yourself.
A:how have I prepared for my final exams
B:whether I can get great grades in the final exams
C:that my school team lost the game because of my fault
D:why did my school team lose the game
小希用如图所示电路来探究串联电路的电压特点.
如图,△ABC与△A′B′C′关于直线l对称,且∠A=98°,∠C′=48°,则∠B的度数为( )