我们在生物学课上学关于繁殖的知识。

We are learning about ___reproduction in biology.

如果我们活得更久但不减缓我们物种的繁殖，会发生什么？

What will happen if we live longer but we don't slow down the ___reproduction of our species?

濒危物种的繁殖是保护主义者关注的重点。

The ___reproduction of endangered species is a key focus for conservationists.