北京顺义牛栏山一中范文

1-5. F F T T F 6. They can be found almost everywhere including northern Europe, EAst Asia, and South America. 7. They may regard a human in the water as a threat to their safety. Sometimes in murky water, they may mistake a human for a natural prey or a wounded animal which would make an easy meal. 8. Because they almost always swim away immediately after biting. 9. However, these attacks average only a single death per year. 10. The truth is that incidences of shark attacks are actually very rare. 11. In fact, human skill more sharks each year than sharks kill people. 12. Almost all studies show that shark attacks are the exception, not the rule. 13. When a shark attacks a human, it is not a calculated choice.