unigravida

例句：

1. 1. The unigravida is a unique and fascinating species.
   这种生物独特且引人入胜。
2. 2. The unigravida has been found in various ecosystems around the world.
   这种生物已在世界各地的各种生态系统中被发现。
3. 3. The unigravida plays an important role in maintaining the balance of the ecosystem.
   这种生物在维持生态系统平衡方面起着重要作用。