SAC

名词 sac:

1. an enclosed space
   同义词：pouch, sack, pocket
2. a case or sheath especially a pollen sac or moss capsule
   同义词：theca
3. a member of the Algonquian people formerly living in Wisconsin in the Fox River valley and on the shores of Green Bay
   同义词：Sauk
4. a structure resembling a bag in an animal

1. A fluid-containing sac or cavity in the body of an organism.
   池有机体体内一种贮存流体的液囊或穴
2. An air-filled sac or structure that aids in the flotation of an aquatic organism.
   气囊水生动植物器官中用来帮助飘浮用的充满气体的囊或结构
3. An organic sac or pouch, such as the udder of a cow.
   (牛的)乳房有机体器官的液囊或袋，如牛的乳房