Ducts and pipes crisscross.

管道纵横交错。

Please fit the ventilation ducts.

请装上通风管道。

Most office buildings have dozens of air ducts and vents.

多数办公楼都有许多的管道和通风口。

Calcium deposits (calcifications) in ducts and other tissues.

腺管或其它组织中的钙沉积(钙化)。

Vapor or fumes may condense on piping, ducts, or stack walls.

蒸气或尘雾可能在管道，烟道或烟囱壁上冷凝。