vitamin K 2
vitamin-k-2的词性：
n.（名词）
1. A crystalline compound, C41H 56O 2, isolated from putrefied fish meal or from various intestinal bacteria, used to stop hemorrhaging and in veterinary medicine as an antidote to certain poisons.
维生素K2：一种晶状化合物，C41H 56O 2，得自于腐烂的鱼肉或多种肠菌，用于止血和兽医上几种毒药的解毒剂