A:①②③
B:②③④
C:①④⑤
D:①②③④⑤
Do you have a baseball bat?
Yes,____ ____ .
Does Ann have a baseball?
No, ____ ____ .
Do Jack and Jim have computers?
Yes, ____ ____ .
Does Chi Yong have a soccer ball?
No,____ ____ .
Do you have a tennis racket?
No,____ ____ .
物体以速度v匀速通过直线上的A,B两点,用时为t.现在物体由A点从静止出发,做加速度大小为a1的匀加速运动到某一最大速度vm,接着做加速度大小为a2的匀减速运动,到B点停止,用时仍然为t,则物体的( )