translation.en: And I think we see this tremendous variation because it's a really effective solution to a very basic biological problem, and that is getting sperm in a position to meet up with eggs and form zygotes.
translation.zh: 我想这些巨大差异的原因 在于这是解决一个非常根本的生物问题的 有效方法 这个问题是,如何让精子能够 遇到卵子使之成为受精卵