air sacs

英 美
  • 肺泡
  • air n.空气;天空;空中;感觉;神态;曲调;装腔作势v.晾干;使通风;广播
名词 air sac:
  1. a tiny sac for holding air in the lungs; formed by the terminal dilation of tiny air passageways

  2. any of the thin-walled extensions of the tracheae of insects

  3. any of the membranous air-filled extensions of the lungs of birds