1
a/the sac of [noun]
常与of连用表示内容物。
A sac of fluid was found in the abdomen.
在腹腔中发现了一个液囊。
囊；液囊
先理解核心含义，再看它在真实句子里的用法。
囊；液囊
a structure resembling a bag in an animal
A sac of fluid was found in the abdomen.
在腹腔中发现了一个液囊。
植物或动物内部通常含有液体的袋状或囊状结构。
A bag or pouch inside a plant or animal that typically contains a fluid.
The spider's venom sac contains a potent toxin.
蜘蛛的毒囊含有一种强效毒素。
Botanists studied the pollen sacs of the flower under a microscope.
植物学家在显微镜下研究了花朵的花粉囊。
The doctor explained that the fluid-filled sac near the joint was harmless.
医生解释说关节附近那个充满液体的囊是无害的。
常与of连用表示内容物。
A sac of fluid was found in the abdomen.
在腹腔中发现了一个液囊。
sac作主语时常用主动动词描述状态变化。
The sac ruptured during the procedure.
手术过程中囊破裂了。
表示位置或范围。
The embryos develop within the sac.
胚胎在囊内发育。
Not this
The fish has an air sack.
Use this
The fish has an air sac.
在生物学中，'sac'指囊状结构，而'sack'一般指袋子，两者拼写相似但含义不同。使用'sac'才是正确的生物术语。
Not this
The doctor found sac near the spine.
Use this
The doctor found a sac near the spine.
'sac'是可数名词单数，前面需要不定冠词'a'或定冠词'the'。汉语中没有冠词，学习者容易遗漏。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
羊膜囊
The amniotic sac protects the developing fetus.
羊膜囊保护发育中的胎儿。
卵黄囊
In early pregnancy, the yolk sac provides nutrients to the embryo.
在怀孕早期，卵黄囊为胚胎提供营养。
气囊
Birds have air sacs that make their respiration more efficient.
鸟类有气囊，使它们的呼吸更有效率。
泪囊
The infection caused swelling in her tear sac.
感染导致她的泪囊肿胀。
花粉囊
Each anther contains two pollen sacs.
每个花药含有两个花粉囊。
妊娠囊
The ultrasound showed a normal gestational sac.
超声波检查显示妊娠囊正常。
Use sac naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
联想 sac 发音像 sack（袋子）：动植物体内的液囊就像一个小袋子，装液体。
语域：formal 常见场景：biology、medicine、anatomy 该词为专业术语，通常出现在生物学、解剖学或医学文献中，属于较正式的书面表达；日常口语中较少使用，泛指袋状物时更常用sack。
这些词都与 /sæk/ 押韵：sack, back, pack, lack, black, track。注意：sock /sɒk/、suck /sʌk/、sick /sɪk/、seek /siːk/ 拼写相近但发音不同。
Dictionary facts from ECDICT, WIKTIONARY.