发布时间：2016-03-09 来源：环球网校 发布人：wyznl
Craig Rogers was sitting on his surfboard, scanning the distance for his next wave, when his board suddenly stopped moving. He looked down and was terrified to see a great white shark biting the front of his board. “I could have touched its eye with my elbow.” says Craig. The shark had surfaced so quietly that he hadn’t heard a thing.
In his horror and confusion, he waved his arms and accidentally cut two of his fingers on the shark’s teeth. He then slid off the opposite side of his surfboard into the water. Then, with Craig in the water and blood flowing from his fingers, the five-meter-long shark simply swam away, disappearing into the water below.
Although sharks are often categorized as killers that hunt and eat as many humans as they can, this is factually inaccurate. Sharks very rarely kill humans.A person has a greater chance of being struck by lightning or drowning in a bath than of being killed by a shark. Only 74 people have been reported killed by great whites in the Iast century. But great white sharks can reach six meters in length and weigh 200 kilograms or more. With frightening jaws that can hold up to 3，000 teeth arranged in several rows, they could very easily kill and eat a helpless human in the water.Why is it，then，that most people survive attacks by great whites? Shark researchers are trying to comprehend the reasons that allow people to escape without being eaten.
The most common explanation is that great whites don’t see well.It has been thought that they mistake people for the seals or sea lions which make up a large part of their diet.There is reason to doubt this, however. Recent information shows that great whites can actually see very well. Also, when attacking seals, great whites shoot up to the surface and bite with great force.When approaching humans，however，they most often move in slowly and bite less hard. They soon discover that humans are not a high-fat meal.“They spit us out because we’re too bony.” says Aidan Martin, director of Reef Quest Center for Shark Research.
Shark researchers like Martin hypothesize that great whites are actually curious animals that like to investigate things. It’s possible that they use their bite not only to kill and eat, but also to gather information.Although such an experience is unlucky for people like Craig Rogers, when sharks bite surfboards or other objects or people，they are likely just trying to learn what they are.
1、After Craig Rogers fell into the water, the shark____.
A、bit his surfboard
B、bit his fingers
2、It is difficult for the author to understand why great whites____.
A、often let humans escape
C、have so many teeth
D、grow to six meters or more
3、Which of the following is closest in meaning to make up in line 2 of paragraph 4?
【答案解析】 本题要求读者根据上下文的语境猜测第四段第二行斜体标出的词组make up的意思。结合make up词组前出现的单词seal和sea lion以及它后面出现的词组a large part of their diet，通过常识我们可以猜出：海豹和海狮应该是鲨鱼的主要食物来源。比对四个选项，我们可以发现选项A(创造)、选项C(增加)和选项D(依靠)在意思上都说不通，代入原文无法构成有意义的一句话。因此只有选项B(是)在意思上和make up最为接近，代入原文也说得通。在本文中，词组make up的意思为：组成，构成。
4、The word their in line 2 of paragraph 4 means_____.
【答案解析】 本题要求读者根据上下文的语境猜测第四段第二行斜体标出的单词their的意思。结合第四段前两行的内容，我们可以很容易推测出，在这里their指代的是the great whites(大白鲨)。因此答案为B。
5、What is the main idea of the fourth paragraph?
A、Great whites eat low-fat, bony meals more slowly.
B、Great whites see well enough to include seals，sea lions，and humans in their diet.
C、We now know great whites don’t mistake humans for other animals.
D、There is reason to doubt that great whites see well enough to attack humans.