Piranhas are South American fish. There are lots of scary stories about them. Most people think that piranhas are very __________________(DANGER) creatures. However, a __________________(SCIENCE) from St Andrews University, Anne Magurran, has recently announced that to call piranhas cruel killers is not fair. They __________________(USUAL) eat fish, plants and insects. According to Professor Anne Magurran, piranhas attack people and animals only when they want to defend themselves. However, most travellers strongly __________________(AGREE) with this point of view. They recommend keeping away from the water where piranhas live. When the fish attack in groups, it is practically __________________(POSSIBLE) to survive. Whatever your opinion of piranhas, this is a __________________(USE) piece of advice one should follow.