Respiratory tract is divided into upper organ outside thorax nose pharynx and larynx and lower respiratory tract organ within thorax trachea bronchi bronchioles alveolar duct and alveoli.3D_站酷海洛_正版图片_视频_字体_音乐素材交易平台

Respiratory tract is divided into upper organ outside thorax nose pharynx and larynx and lower respiratory tract organ within thorax trachea bronchi bronchioles alveolar duct and alveoli.3D