Trochidae

例句：

1. 1. The trochoid is a shape that resembles ahorseshoe.
   扭叶形是一种类似于马蹄的形态。
2. 2. The trochoid isused in the study of fluid flow.
   扭叶形在流体流动研究中被使用。
3. 3.The trochoid is a commonshape in the design of aircraft wings.
   扭叶形是飞机机翼设计中常见的形状。