世系
lineage; genealogy; family tree
世袭
succession; inheritance; hereditary
实习
to practice; field work; to intern; internship
世袭之争
succession struggle; dispute over inheritance
二项式系数
a binomial coefficient (math.); the number of combinations
吞噬细胞
phagocyte (cell that ingests and destroys foreign matter)
小吞噬细胞
microphage (a type of white blood cell)