A:2
B:22
C:5
D:8
He's never rude. I think he's one of the most _______ boys in his class.
已知M={(x,y)|x2+2y2=3},N={(x,y)|y=mx+b}.若对于所有的m∈R,均有M∩N≠∅,则b的取值范围是( )
一Not yet.I'm doing it right now.