汽车在水平地面上因故刹车,可以看做是匀减速直线运动,其位移与时间的关系是:s=16t﹣2t2(m),则它在停止运动前最后1s内的平均速度为( )
A:6m/s
B:4m/s
C:2m/s
D:1m/s
一 We'll have a quiz at the end of class.
一 Study harder, and we'll do better.