If I see you through the glass, the object is going on some trajectory, which has got both up and down and horizontalmotion.
如果我透过窗户看你，物体在一些轨道上，有上升和下降，也有水平运动。
2
Some movements involving primarily vertical or horizontal motions of the body as a whole, in which rotations can be ignored, can be studied using simple equations of linear motion in three dimensions.
有些运动主要涉及整体的垂直或水平运动，其中转动可以忽略，可以用三维线性运动的简单方程来研究。
3
The load sway of crane is mainly generated by its horizontalmotion.