wigwag

风中的柳条轻轻摇动，像是在跟路人打招呼。

The willow branches ___wigwag gently in the breeze, as if greeting passersby.

小狗看到主人回家，尾巴兴奋地左右摇摆。

The puppy's tail began to ___wigwag excitedly when its owner came home.

旗帜在屋顶上随风摇动，发出轻微的拍打声。

The flag on the rooftop continued to ___wigwag in the wind, making a soft flapping sound.