down-feather的用法和樣例：
例句
- In a plumulaceous feather, barb ridges grow straight without any helical movement.
在絨羽上，羽枝脊則直直生長(cháng)，不做螺旋形移動(dòng)。 - Common allergens include pollen, animal dander, down feathers, mites, chemicals, and a variety of foods.
常見(jiàn)的過(guò)敏原包括花粉，動(dòng)物皮屑，絨羽，螨類(lèi)，化學(xué)品，以及各種食品。
詞匯搭配
- knock someone down with a feather 使某人十分驚奇...
