性腺

例句：

1. 1. The male and female reproductive organs are called gonads.
   男性和女性的生殖器官被称为性腺。
2. 2.The study of the functioning of theseorgans is known as endocrinology.
   研究这些器官功能的学科称为内分泌学。
3. 3. In humans, the testes arethe primary sex glands responsible for producingsperm.
   在人类中，睾丸是主要负责产生精子的性腺。