英语语法分析

It only takes one sperm to fertilize an egg.

只需一个精子就可以使卵受精。

《柯林斯英汉双解大词典》

Since only one female usually lays eggs in a given larva, it would pay her to produce one male only, because this one male could fertilize all his sisters on emergence.

因为通常只有一只雌性在一个特定的幼虫中产卵，所以它只会产生一只雄性，因为这只雄性可以在孵化时使它所有的姐妹受精。

If they are females, a male may fertilize their eggs.

若它们都是雌性，就要一只雄性来孵化她们的卵。