They kept moving in a circle around the swimmers.
他们围绕着游泳的人不停地转着圈。
The children stood in a circle.
孩子们站成一圈。
She walked the horse round in a circle.
她牵着马兜圈子。
His nineteen-oh-nine painting "Dance" shows five women energetically dancing in a circle.
VOA: special.2010.03.24
In other words, you don't have to be moving actually in a circle to have the acceleration.
也就是说,你不必真的在一个圆上运动以获得相应的加速度
Suppose the particle is not moving in a circle, but does this.
假设这个质点不是做圆周运动,而是这样
应用推荐