半月瓣

例句：

1. 1. The butterfly's wings are adorned with delicate, semicircular appendages.
   蝴蝶的翅膀上装饰着精致的、半圆形的附属物。
2. 2. The plant's petals are formed by a series of semicircular flaps.
   这种植物的花瓣由一系列半圆形的褶皱组成。
3. 3. The heart is divided into four chambers, each with a semicircular opening.
   心脏被分为四个腔室，每个都有半圆形的开口。