下列说法正确的是[ ]

A．物体受到的合外力方向与速度方向相同时，物体做加速直线运动

B．物体受到的合外力方向与速度方向成锐角时，物体做加速曲线运动

C．物体受到的合外力方向与速度方向成钝角时，物体做减速直线运动

D．物体受到的合外力方向与速度方向相反时，物体做减速直线运动

—Our P.E. teacher isn't as young as he _____, is he?

—No, but he is one of _____ in our school.[ ]

A. looked; the youngest teacher

B. looks; the youngest teachers

C. looks; the oldest teachers

D. looked; the oldest teacher