—I'll have them ______and give away to the children who don't have bikes.
A:used up
B:given up
C:fixed up
D:set up
从某一高度处水平抛出一个物体,它落地时速度是50m/s,方向与水平方向成53°角.(g取10m/s2,cos53°=0.6,sin53°=0.8)求:
下列结构中,植物细胞和动物细胞都具有的结构是( )