A:In an hour.
B:For an hour.
C:One hour ago.
My birthday is ___________ May.
平行四边形内角平分线能够围成的四边形是( )
定义在R上的奇函数f(x),满足f( 12 )=0,且在(0,+∞)上单调递减,则xf(x)>0的解集为( )