Ключевые слова: africa, african, alone, animal, animals, artiodactyla, even toed, even toed ungulates, fauna, hippo, hippopotamidae, hippopotamus, hippopotamus amphibius, hippopotamuses, hippos, hoofed animals, lake, mammal, mammalia, mammals, natural, nature, one, one animal, only, river, species, sunken, surface, under, underwater, ungulate, water, wild life, wildlife, zoo,