SSS 2010-12-03
时间：2019-01-08 作者：英语课 分类：Scientific American(十二)月
They’re everyone’s worst nightmare when it comes to swimming in the ocean: great white sharks. That’s despite the fact that the number of fatal shark attacks annually 1 can usually be counted on the fingers of one still attached hand. But a new study finds that until great whites get at least three meters long, they’re less and more. Because a full-force bite could wind up hurting them.
In research published in the Journal of Biomechanics, scientists used 3-D computers models and advanced engineering techniques to study how sharks hunt and kill their food.
Great whites have jaws 2 and teeth that are perfect for a powerful chomp 3 on prey 4 ranging from small fish to large marine 5 mammals. But the researchers were surprised to find that a shark less than three meters long only looks like it could manage that killer 6 bite. Because it has not developed enough stiff, mineralized cartilage yet. A bite that would be lethal 7 to a large marine mammal could damage the shark’s jaws.
The finding may explain why the few shark attacks that do happen on people are rarely fatal—until it’s pretty big, the great white’s reputation is worse than its bite.
Thanks for the minute. For Scientific American’s 60-Second Science. I'm Cynthia Graber.
- Many migratory birds visit this lake annually.许多候鸟每年到这个湖上作短期逗留。
- They celebrate their wedding anniversary annually.他们每年庆祝一番结婚纪念日。
- The antelope could not escape the crocodile's gaping jaws. 那只羚羊无法从鱷鱼张开的大口中逃脱。
- The scored jaws of a vise help it bite the work. 台钳上有刻痕的虎钳牙帮助它紧咬住工件。
- I lost a tooth while chomping on a French baguette!我啃法棍面包时，崩掉了一颗牙！
- They just chomp on tundra, nap a few hours and feast again.它们只是在苔原上大嚼特嚼，睡上几小时，接着再吃。
- Stronger animals prey on weaker ones.弱肉强食。
- The lion was hunting for its prey.狮子在寻找猎物。
- Marine creatures are those which live in the sea. 海洋生物是生存在海里的生物。
- When the war broke out,he volunteered for the Marine Corps.战争爆发时，他自愿参加了海军陆战队。
- Heart attacks have become Britain's No.1 killer disease.心脏病已成为英国的头号致命疾病。
- The bulk of the evidence points to him as her killer.大量证据证明是他杀死她的。