1. Birds have a complex system of air sacs to aid breathing.
鸟类拥有复杂的呼吸气囊系统来辅助呼吸。

2. The balloon's air sac expanded as it was blown up.
气球的气囊随着吹气而膨胀。

3. Some fish use an air sac for buoyancy.
某些鱼类利用气囊来维持浮力。

A: Did you know that birds use air sacs to breathe?
A：你知道吗？鸟类利用气囊来进行呼吸。

B: Yes, their air sac system is quite efficient.
B：是的，它们的呼吸气囊系统非常高效。

1) 生物学中的气囊

2) 充满空气的囊状结构

3) 填充空气的小袋

1. 气囊

e.g. The fish has a large air sac.
这种鱼有一个巨大的气囊。

noun

1. A small cavity or pouch filled with air, especially in a biological organism.

Synonym: pouch, bladder, sac