The average speed of the trains in China is increasing. 中国火车的平均速度一直在提高。
Use a graphing program such as Excel to graph the second distance on the x-axis and average speed on the y-axis. 计算气球上每个点相对银河系的平均速度。
He usually drives at a moderate speed. 他通常中速驾驶。
Sharpshooter Lakers to complete all the projects, he trained in doing the movements carefully as possible, moving as far as possible in order to speed completion. 湖人神射手完成了所有的项目,他在训练中尽量小心翼翼的做着动作,移动中尽量以中速完成。