Dolphins are not fish. They are mammals (1) _________________________ live in water. Dolphins
are (2) _______________________ the most intelligent animals on earth. Although they can be found in (3) ______________________ oceans in the world, dolphins prefer coastal waters and bays. The size of dolphins can vary greatly. The smallest dolphin is just about 50 kg in (4) ______________________ and 1.2 metres in length while (5) _____________________________ largest one can weigh up to 8,200 kg and is 100 metres (6) _________________________. Dolphins eat (7) _______________________________ fish. A female dolphin gives birth (8) __________________________ one calf every two years after a (9) _______________________
period of eleven or twelve months. A dolphin can normally live from twenty-five to sixty-five years and some species of dolphins can even live longer. Dolphin populations are at risk (10) ____________________________ to the pollution of their habitat and accidental entrapment in fishing nets.
