【正确答案】 D

【答案解析】[解析] 26-28
Most people picture sharks as huge, powerful, frightening predators, ready at any moments to use their sharp teeth to attack careless swimmers without provocation. But, (26) people may have some wrong ideas on the conception of sharks.
First, there are 350 species of shark, and not all of them are large. They range in size from the dwarf shark, which can be only 6 inches long and can be held in the pain, of the hand, to the whale shark, which can be mere than 55 feet long.
Second, the different species of shark vary tremendously in the number and type of teeth. A shark can have from one to seven sets of teeth at the same time, and some types of shark can have several hundred teeth in each jaw. It is true that the fierce and predatory species do possess extremely sharp and brutal teeth used to rip their prey apart: (27) many other types of shark, however, have teeth more adapted to grabbing and holding than to cutting and slashing.
Finally, not all sharks are predatory animals ready to strike out at humans. In fact, only 12 of the 350 species of shark have been known to attack humans, and a shark needs to be provoked in order to attack. (28) The types of shark that have the worst record with humans are the tiger shark, the bull shark, and the great white shark. However, for most species of shark, even some of the largest types, there are no known instances of attacks on humans.

26. What is the main purpose of this passage?

[试题分析] 本题考查考生对文章信息的综合能力。
[详细解答] 文中提到“people may have some wrong ideas on the conception of sharks”，而且在随后的内容中用具体的例子证明了这一点。故选D。

【正确答案】 D

【答案解析】[解析]
Which of the following is NOT true about a shark’s teeth?

[试题分析] 本题考查考生对信息细节的理解。
[详细解答] 文中提到“It is true that the fierce and predatory species do possess extremely sharp and brutal teeth…，many other types of sharks，however，…”“however”后面所提到的鲨鱼牙齿很显然是与前面所提到的牙齿类型不一样。故选D。

【正确答案】 A

【答案解析】[解析]
What can we infer from the passage?

[试题分析] 本题考查考生对文章的推理能力。
[详细解答] 选项显然是关于什么样的鲨鱼最不可能攻击人类。文中提到最喜欢攻击人类的鲨鱼为“tiger shark，the bull shark，the great white shark”，那么dwarf shark显然不属于此列。故选A。