30 species of whales, dolphins and porpoises.

30种鲸，海豚和鼠海豚。

Porpoises and sharks are natural enemies.

海豚和鲨鱼是天然仇敌。

Porpoises and sharks are natural enemies.

海豚和鲨鱼是一对天敌。

In 1928 some porpoises were photographed.

1928年，有人拍摄到了海豚。

Porpoises and sharks are natural enemies.

海豚在孩子们面前跳舞。