The circular arc gear drive is one kind of axial conjugate gear drive which meshes in points. The movement transmission depends contact mark along the endmotion to realize.
圆弧齿轮传动是一种轴向共轭、点啮合制的齿轮传动，运动的传递依靠接触迹沿轴向移动实现。
2
The shift from silent to sound film at the end of the 1920s marks, so far, the most important transformation in motion picture history.
20世纪20年代末无声电影向有声电影的转变标志着迄今为止电影史上最重要的转变。
3
If there was motion in the current frame, add a rainbow piece between the end of previous rainbow piece and the current motion position.