物体A,B的x﹣t图象如图所示,由图可知( )
A:从第3 s起,两物体运动方向相同,且vA<vB
B:两物体由同一位置开始运动,但物体A比B迟3 s才开始运动
C:在5 s内A的位移较大,5 s末A,B相遇
D:5 s内A,B的平均速度相等
无性生殖和有性生殖的本质区别是( )
——__________Internet business traditional business in the past few years? ——Not really.
His mum wanted____ (buy) a book for him.