helical motion的用法和樣例：
例句
- Even slight spiraling motion in a square pipe increases the tendency of particles to be maintained in suspension.
水流在方管中稍有一些螺旋運動，將增加泥沙懸浮在水中的作用。 - It is the sufficient and necessary condition that the velocities of three non-collinear points in a rigid body can determine a screw motion of the body.
這是物體上非共線三點的速度能確定此物體螺旋運動的充分必要條件。
