CÓ GIẢI THÍCH THÌ TỐT LẮM LUÔN (1)………......... many years people believed that the cleverest animals (2)……......….. man were chimpanzees. Now, however, there is proof that dolphins may (3)…….....….. even cleverer than these big apes. Although a dolphin lives in the (4)……..........….., it is not a fish. It is a mammal. It is in many ways, therefore like human beings. Dolphins have a simple language. They are (5)…........…….. to talk to one another. It may be (6)……..........….. for man to learn how to talk to dolphins. But this will not be easy (7)…….....….. dolphins cannot hear the kind of sounds that man can make. If man wants to talk to dolphins, therefore, he will (8)……........….. to make a third language which both he and the dolphins can understand. Dolphins are (9)….........…….. very friendly towards man. They often follow ships. There are many stories of dolphins guiding (10)…................…….. through difficult and dangerous water.