Sharks have lived in the oceans for over 450 million years, long before dinosaurs appeared

Sharks have lived in the oceans for over 450 million years, long before dinosaurs appeared. There are now about 360 species of sharks, whose size, behavior, and other characteristics differ widely.
Every year, we catch and kill over 100 million sharks, mostly for food and for their fins. Dried shark fins are used to make shark fin soup, which sells for as much as $50 a bowl in fine Hong Kong restaurants. Other sharks are killed for sport and out of fear. Sharks are vulnerable(易受伤的) to overfishing because it takes most species 10 to 15 years to begin reproducing and they produce only a few offspring（后代）.
Influenced by movies and popular novels, most people see sharks as people-eating monsters. This is far from the truth. Every year, a few types of shark injure about 100 people worldwide and kill about 25. Most attacks are by great white sharks, which often feed on sea lions and other marine（海洋的） mammals. They sometimes mistake human swimmers for their normal prey, especially if they are wearing black wet suits.
If you are a typical ocean-goer, your chances of being killed by an unprovoked（非受挑衅而发生的）attack by a shark are about 1 in 100 million. You are more likely to be killed by a pig than a shark and thousands of times more likely to get killed when you drive a car.
Sharks help save human lives. In addition to providing people with food, they are helping us learn how to fight cancer, bacteria, and viruses. Sharks are very healthy and have aging processes similar to ours. Their highly effective immune system allows wounds to heal quickly without becoming infected, and their blood is being studied in connection with AIDS research.
Sharks are among the few animals in the world that almost never get cancer and eye cataracts（白内障）. Understanding why can help us improve human health. Chemicals taken from shark cartilage（软骨）have killed cancerous tumors in laboratory animals, research that someday could help prolong your life.
Sharks are needed in the world’s ocean ecosystems. Although they don’t need us, we need them. We are much more dangerous to sharks than they are to us. For every shark that bites a person, we kill one million sharks.
【小题1】Which of the following is NOT a reason why people kill sharks?A．People kill sharks for food.B．People kill sharks for sport.C．People kill sharks out of fear.D．People kill sharks because they often attack swimmers.【小题2】According to the passage, which of the following statements is NOT true?A．There are many different species of sharks, but only a few of them are dangerous to humans.B．Sharks never get ill.C．Sharks are a valuable resource for human.D．Sharks play an important role in the ocean ecosystem.【小题3】It can be inferred from the passage that .A．movies have given people the wrong impression of sharksB．most sharks are dangerous to humansC．sharks will attack anyone who is wearing blackD．it is dangerous to swim in the ocean【小题4】The underlined word “prolong” in the last but one paragraph means .A．saveB．protectC．lengthenD．improve【小题5】The best title for the passage would be .A．Are Sharks Dangerous?B．Sharks And HumansC．Sharks: Humans’ FriendsD．Sharks Help Save Human LivesD

(答案→)D 解析：文章讲的人类捕杀鲨鱼的原因，有一部分在于害怕鲨鱼，但是鲨鱼很少伤害人类，而且对人类很有益，对生态系统也是有帮助的。【小题1】细节题：从文章第二段的内容可知人们杀死鲨鱼是因为食物，运动和害怕，没有说是因为鲨鱼经常袭击游泳者。选D【小题2】细节题;从第六段的句子：Sharks are among the few animals in the world that almost never get cancer and eye cataracts（白内障）.可知鲨鱼很少得癌症和白内障，但不是说鲨鱼就不会得病。选B【小题3】细节题：从第三段的句子：Influenced by movies and popular novels, most people see sharks as people-eating monsters.可知是电影给了人们对鲨鱼的错误的观点。选A【小题4】猜词题：从前面的句子：Chemicals taken from shark cartilage（软骨）have killed cancerous tumors in laboratory animals,鲨鱼软骨里面的化学物质可以杀死癌细胞，可知是延长人的寿命。选C【小题5】主旨题:文章讲的是鲨鱼很少伤害人类，而且对人类很有益，对生态系统也是有帮助的，也就是鲨鱼—是我们的朋友。选C

对的，就是这个意思