A:puzzled; puzzling
B:puzzling; puzzled
C:puzzled; puzzled
D:puzzling; puzzling
单项式23x2ym与多项式x2y2+12x3y4+13的次数相同,求m的值.
我国实行计划生育工作中对已生育的育龄妇女采用结扎输卵管的措施,其作用是( )