正螺旋

例句：

1. 1.The screw has a helical shape, which is characteristic of a right-handed spiral.
   这个螺丝有一个螺旋状的形状，这是右手螺旋的典型特征。
2. 2.The gears on the car are designed to have a right-handed spiral motion.
   汽车上的齿轮设计成有右手螺旋运动。
3. 3.The machine tool has a right-handed spiral cutting edge.
   这台机床有一个右手螺旋切削刃。