four-membered ring

例句：

1. 1. The structure of the four-membered ring is very complex.
   这个四成员环的结构非常复杂。
2. 2. The tetrahedral ring is a common shape in crystal chemistry.
   四面体环是晶体化学中常见的形状。
3. 3. This ring has been used in many different applications, including as a structural element in bridges and towers.
   这个环在许多不同的应用中使用过，包括作为桥梁和塔楼的结构元素。