translation.en: Now, young dolphins learn a lot as they're growing up, and they use their teenage years to practice social skills, and at about the age of nine, the females become sexually mature, so they can get pregnant, and the males mature quite a bit later, at around 15 years of age.
translation.zh: 年轻海豚在它们的成长过程中要学习很多本领， 它们在青春期要练习社交技巧， 雌性海豚在9岁左右， 进入生理成熟阶段，就会有生育能力， 雄性海豚成熟期会稍微晚一点， 大约在15岁的时候。