0 a sea mammal that is large, smooth, and grey, with a long, pointed mouth
1 a sea mammal that looks like a large fish with a pointed mouth
After studying dolphins, people built submarines to move quickly in the ocean and stay under the water for a long time.
Dolphins move quickly in the water not only to be safe from danger.
Dolphins use their tails to go faster and their fins to change direction.
Whales and dolphins look like fish, but they’re really mammals!
While many other animals, such as chimpanzees and dolphins, live in groups and communicate, scientists don’t know for certain whether they can talk and share complicated ideas.
He notices that the dolphin's bright colors afford a warning to his enemies, and give them a chance of escape.
He tapped out a distress call which the dolphins could relay to the swimmers.
I tell you there's a shark swimming in these waters—a shark so big that by comparison Port Royal Tom would seem like a dolphin.
