turtle graphics

例句：

1. 1. The turtle graphics are used to createa smooth transition between the two screens.
   海龟图形用于在两个屏幕之间创建平滑过渡。
2. 2. The turtle graphics were designed tobe easy to use and understand for beginners.
   海龟图形设计为初学者易于使用和理解。
3. 3. The turtle graphics were used toillustrate the concept of symmetry in mathematics.
   海龟图形被用来说明数学中对称的概念。