鼓风口

例句：

1. 1. The wind direction is indicated by the gauze on the top of the flag.
   风向由旗顶的纱线表示。
2. 2. The gauze indicates the direction of the wind.
   纱线指示风向。
3. 3. The gauze was used to indicate the direction of the wind.
   使用纱线来指示风向。