1. The testis is the male reproductive organ responsible for producing sperm.
(睾丸是男性的生殖器官,负责产生精子。)
2. In some animals, such as fish and reptiles, the testis is located internally, while in mammals it is located in the scrotum.
(在一些动物,如鱼类和爬行动物中,睾丸位于内部,而在哺乳动物中则位于阴囊中。)