For various reasons£¬sharks£¬regarded as a kind of valuable sea animal£¬are hunted or killed each yea r.For exam ple£¬people hunt sharks for sport£¬food and medicine.In Asia£¬people think shark meat£¬especially a special king of soup made from shark fins£¬is good to eat.In addition£¬shark liver oil is a popular supplier of vitamin A which can improve people's health.That's why the international market for some kinds of