systemic veins的用法和樣例：
例句
- Their predominant loci are the inferior vena cava and large veins of thighs.
最好發的部位是下腔靜脈與大腿的大靜脈。 - Pancreatic acini and pancreatic islets distribute around main veins, acinar cells being stained into navy blue are closely arranged.
胰腺腺泡和胰島分佈於肝臟內大靜脈周圍，腺泡細胞染色深藍色。
