First place a bucket on the board, and wait for bad weather., When it rains, the bucket fills with water., It gets heavier and heavier and , lowers the board on one side., Consequently, the other end goes up, and lifts the pen into the pencil sharpener., The wind makes the blades at the top rotate., The cogs transfer the rotation and, make the sharpener spin and sharpen the pen..

7.3 Processes

打印
嵌入

排行榜

视觉风格

选项

切换模板

恢复自动保存：？