小鸭子在水面上拍打着翅膀。

The duckling was ___flapping its wings on the water surface.

窗帘在风中不停地拍打着窗户。

The curtains were ___flapping against the window in the breeze.

在美式英语中，单词'water'中的't'经常发成闪音。

In American English, the 't' in 'water' often turns into a ___flapping sound.