建议给宠物绝育以控制宠物数量。

It’s recommended to ___neuter or ___spay pets to control the pet population.

我们决定给狗狗做绝育手术，这样它就不会再繁殖了。

We decided to ___neuter our dog so it wouldn't reproduce anymore.

在英语中，单词'book'属于中性词。

In English, the word 'book' is of ___neuter gender.