circular flue

例句：

1. 1. The circular flue is used to exhaust the exhaust gases from the furnace.
   环形烟道用于将炉膛的废气排出。
2. 2. The chimney of the house is designed to direct the smoke upwards.
   房子的烟囱设计用来将烟雾向上引导。
3. 3. The duct is made of metal and is used for carrying air or gases.
   该管道由金属制成，用于输送空气或气体。