一辆汽车刹车后做匀减速直线运动，初速度为10m/s，加速度的大小为2m/s²，则汽车在6s末时的速度大小和6s内的位移大小分别是 [ ]

A．0和25m

B．0和24m

C．2m/s和24m

D．2m/s和25m

What a pity! I ______in Hainan two more days，but something urgent needed to be dealt with back home.

A．must have stayed

B．needn't have stayed

C．may have stayed

D．could have stayed