first septum

例句：

1. 1. The first septum is the thinnest part of the eardrum.
   第一隔膜是鼓膜最薄的部分。
2. 2.The first septum can be seen as a protective barrier between the ear and the environment.
   第一隔膜可以被视为耳朵与环境之间的保护屏障。
3. 3. The first septum plays an important role in maintaining the balance of the inner ear.
   第一隔膜在维持内耳平衡方面起着重要作用。