A:命题“若”的逆否命题为“若”
B:若为假命题,则p、q均为假命题
C:“”是“”的充分不必要条件
D:对于命题,均有
已知:如图,在△ABC中,∠ACB=90°,CD⊥AB,垂足是D,BC=6,BD=1.求AD=____
My grandfather is fond of talking about the good old days, ___ is often the case with old people.