male doctor protects lungs with shield, lung protection health concept illustration. - 細支氣管 幅插畫檔、美工圖案、卡通及圖標
male doctor protects lungs with shield, lung protection health concept illustration. - 細支氣管 幅插畫檔、美工圖案、卡通及圖標健保和醫療
the alveoli are the final branchings of the respiratory tree and act as the primary gas exchange units of the lung. - 細支氣管 幅插畫檔、美工圖案、卡通及圖標