A.小于當?shù)匾羲?br /> B.等于當?shù)匾羲?br /> C.小于或等于當?shù)匾羲?br /> D.大于當?shù)匾羲?/p>
A.等于喉部臨界流速 B.等于當?shù)匾羲?br /> C.大于當?shù)匾羲?br /> D.小于當?shù)匾羲?/p>
A.dp2>0,dC2<0,dm=0 B.dp2<0,dC2>0,dm>o C.dp2>o,dC2<0,dm>0 D.dp2<0,dC2=0,dm=0