小鸟拍打着翅膀飞向树梢。

The little bird flapped its ___wings and flew to the treetop.

图书馆的东翼专门用于存放历史书籍。

The east ___wing of the library is dedicated to historical books.

激进派呼吁党内进行更深层次的改革。

The radical ___wing is calling for deeper reforms within the party.

蝴蝶在花丛间轻盈地飞来飞去。

The butterfly ___fluttered gracefully among the flowers.

鸟的翅膀和飞机的机翼虽然形状不同，但都用于飞行。

The bird's wings and the airplane's ___wings serve the same purpose for flight, despite their different shapes.