—Are Mike and Jack having lunch at school now?
— .
A:No, they are
B:Yes, they do
C:No, they aren't
D:No, they don't
若sinA=23,则A的取值范围是( )
在等比数列{an}中,若a1a2a3=2,a2a3a4=16,则公比q= ( )
在△ABC中,内角A,B,C的对边分别为a,b,c,且3cosAcosB+1=3sinAsinB+cos2C.