first sepal primordium

例句：

1. 1. The first sepal of the flower is a crucial partin its growth process.
   花朵的第一枚花瓣在生长过程中起着至关重要的作用。
2. 2. The discoveryof this primordium has revolutionized our understanding of plant development.
   这一原始花序的发现极大地改变了我们对植物发育的理解。
3. 3. In the study of plant evolution, scientists often focus on the first sepals as they are the earliest visible partsof a flower.
   在植物进化研究中，科学家们通常关注最初的花瓣，因为它们是花朵最早可见的部分。