demicircular

例句：

1. 1. The circle is the most basic shape in mathematics.
   圆是数学中最基础的形状。
2. 2. The car has a circular design.
   这辆车有一个圆形的设计。
3. 3. The moon is a perfect example of a circular object.
   月亮是一个完美的圆形物体的例子。