— I drove my car at a speed of 150 kilos an hour this afternoon. It was great fun!
— Did you go crazy? You ______________yourself.
A:might kill
B:could have killed
C:could kill
D:must have killed
某地区海拔多在500米以上,山峦连绵起伏,山高谷深,崎岖不平。山谷间常有吊索桥,人们来往其间。根据文字描述,这一地区的地形是( )
某同学在百米比赛中,以6.0m/s的速度迅速从起点冲出,到50m处的速度是8.2m/s,在他跑的全程的中间时刻即t1=6.25s时的速度为8.3m/s,最后以8.4m/s的速度冲过终点,他在百米比赛中平均速度的大小为____ m/s.