—He's really a hard-working boy.
A:was still
B:was always
C:was actually
你认为怎样算简便就怎样算.
0.625×8+0.375×8
抛物线y2=-12x的准线与双曲线x29-y23=1的两条渐近线所围成的三角形的面积等于( )
下列有关青春期的叙述错误的是( )