质点做直线运动的图象如图所示，规定向右为正方向，则该质点在前8s内平均速度的大小和方向分别为

A．0.25m/s 向右

B．0.25m/s 向左

C．lm/s 向右

D．lm/s 向左

16. You cannot be too careful. Which of the following sentences doesn’t have the same meaning of the underlined sentence? _____

A．You cannot be careful at all.

B．You cannot be over careful.

C．You cannot be careful enough.

D．You cannot take enough care.