Прочитай текст. Определи, какие из приведённых утверждений являются верными (1 – True), какие неверными (2 – False) или о чём в тексте не сказано (3 – Not stated Dolphins are mammals. Most live in oceans, where water is salty. But some live in rivers – there are oceanic dolphins and river dolphins. Dolphins are usually from 1.5 metres to 4 metres long. Dolphins breathe air. A dolphin's nose is on top of its head so the dolphin can easily breathe on the surface of the water. The skin of a dolphin is soft and smooth. Dolphins do not sleep in a normal way. They have two sides of their brain, which they use to sleep. One side sleeps, while the other side does not sleep. They keep one eye open to watch for enemies while they sleep. Dolphins also swim in circles when they are sleeping with one of the eyes open to watch out for danger. Dolphins are the friendliest animals in the sea and there are a lot of stories about dolphins which help sailors. Dolphins are clever animals. They look after other dolphins when they are ill, care for very young dolphins and protect the weakest dolphins. Some scientists think that dolphins have a language, other scientists believe that dolphins communicate with each other without words. 1. Dolphins can live in rivers. 1) True 2) False 3) Not stated 2. Dolphins can live without air. 1) True 2) False 3) Not stated 3. When dolphins sleep, both parts of their brains work. 1) True 2) False 3) Not stated 5. A dolphin does not close one of its eyes when it sleeps. 1) True 2) False 3) Not stated 6. Scientists believe that people can learn the dolphins’ language. 1) True 2) False 3) Not stated