Either of two spongy,saclike respiratory organs in most vertebrates,occupying the chest cavity together with the heart and functioning to remove carbon dioxide from the blood and provide it with oxygen.

• 肺大多数脊椎的物的两个海绵状的，囊状的呼吸器官，它和心脏一起占据胸腔，作用是从血液中排出二氧化碳和使血液吸收氧气。