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。