upper flagellum

例句：

1. 1. The upper flagellum is responsible for propelling the spermatozoa through the female reproductive tract.
   上鞭毛负责将精子通过雌性生殖道输送。
2. 2. During the mating process, the upper flagellum of the male spermatozoon penetrates the vaginal wall andenters the oviduct.
   在交配过程中，雄性精子的上鞭毛穿透阴道壁进入输卵管。
3. 3.The upper flagellum is a specialized structure that allows the sperm to move rapidly through the female reproductive tract.
   上鞭毛是一种特殊结构，使精子能够快速通过雌性生殖道。