不仅单位时间内移动的距离不变，而且其方向也不改变。

Not only does the distance traveled in unit time remain the same but the direction does not change as well.

youdao

不仅单位时间内移动的距离不变，而且其方向也不改变。

Not only does the distance traveled in unit time remain the same but the direction does not change as well.

youdao