原版-【3D演示】呼吸系统（原版+字幕版）

热门回复：

• 刘忠宝环球粉丝会首席:The respiratory system provides the body with the ability to perform gas exchange with our external environment .It consists of an extensive network of Gretchen tubes with cyclic endings are in close contact with blood vessels It is at these points that oxygen enters the blood and carbon dioxide exits anatomically we divide the respiratory system into two distinct parts the upper respiratory tract and the lower respiratory tract.
• sxr1223:up主发些更有知识含量的呗
• 夜行性クミン:求字幕软件(=・ω・=)
• 踏实的大王花:这是那个软件的 广告吧!
• 钩钩同学:好好学习❤