Question

    Elephants born without tusks(长牙) normally make up just 2 to 6 percent of the herd population. However, that is not the case at Mozambique’s Gorongosa National Park, where 33 percent of female elephants born after the country’s civil war ended in 1992 are tuskless. While that might be just a coincidence(巧合), Joyce Poole, an elephant behavior expert, has another theory.

The researcher thinks we may be witnessing an unnaturally evolution of the species due to the hunting of the elephants for their valuable tusks. Unlike our permanent teeth, tusks of elephants grow throughout the animal’s life, becoming longer and thicker with age. For decorative purposes, poachers usually first target older males due to their impressive tusks, and females are not spared either. As a result, in areas where hunting goes unchecked for long, the number of tuskless females increases. This allows them to gain a biological advantage, resulting in a larger than average population of female offspring (后代)with no tusks.

Poole believes this phenomenon explains the rise in the number of tuskless females at Gorongosa National Park. The researcher says before the war, the park was home to over 4,000 elephants. However, by the time the conflict ended in 1992, about 90 percent of the elephants had been slaughtered for tusks to help finance weapons and meat to feed the soldiers. Of the less than 200 survivors, over 50 percent of the females had no tusks. Hence, it is not surprising that the park’s tuskless elephant population has grown greatly.

So far, the hunting has largely influenced female elephants. Poole explains, “Very few males are tuskless because males require tusks for fighting. Without tusks, males have a much harder time breeding and do not pass on their genes(基因) as often as tusked ones.” If the hunting of males for tusks continues at this pace, it could result in a generation of elephants with much smaller tusks.

1.How does the writer draw readers’ attention to the topic?

A.By comparing figures. B.By offering explanation. C.By giving an example.              D.By introducing an expert.

2.What might be the reason for the increase of tuskless females?

A.Illegal hunting. B.Pure coincidence.

C.Natural evolution. D.Effective protection.

3.What does the underlined word “slaughtered” in Paragraph 3 mean?

A.Raised. B.Protected. C.Killed. D.Trained.

4.What is the text mainly about?

A.The future of African elephants.

B.The protection of African elephants.

C.The increasing number of tuskless elephants.

D.The genetic consequence of hunting elephants.

5.In which section of a newspaper may this text appear?

A.Health. B.Science. C.Education. D.Finance.

Answer

1.A

2.A

3.C

4.D

5.B

【解析】

本文是说明文。因为宝贵的象牙，大象被非法狩猎，这也导致它们的后代无象牙的大象数量超出了平均数量。

1.推理判断题。在第一段中提到“Elephants born without tusks(长牙) normally make up just 2 to 6 percent of the herd population”和“33 percent of female elephants born after the country’s civil war ended in 1992 are tuskless”，出生时无象牙的大象占总数的2%至6%，而在莫桑比克的Gorongosa国家公园，雌象中有33%没有象牙。通过无象牙的大象的数据比较，引起大家对话题的关注。故选A项。

2.细节理解题。根据第二段中“due to the hunting of the elephants for their valuable tusks”和“in areas where hunting goes unchecked for long, the number of tuskless females increases”可以推断，因为宝贵的象牙，大象被非法狩猎，导致无象牙的雌象数量增加。故选A项。

3.词句推测题。根据划线词后面的“…for tusks to help finance weapons and meat to feed the soldiers”，因为象牙，那些大象被猎杀，以帮助资助武器，也为士兵提供肉类。因此可以推测slaughter意思为“杀死”。故选C项。

4.主旨大意题。根据第二段中“…gain a biological advantage, resulting in a larger than average population of female offspring (后代)with no tusks（这使得它们获得了生物学上的优势，导致雌象后代无象牙大象的数量超过平均数量）”和第四段中“If the hunting of males for tusks continues at this pace, it could result in a generation of elephants with much smaller tusks（如果雄性大象的猎杀继续以这样的速度进行，可能会产生象牙更小的一代大象）”可知，因为非法狩猎，大象失去象牙，导致它们后代无象牙或者象牙更小。文章是关于非法狩猎大象的遗传后果的。故选D项。

5.推理判断题。本文说明了因为宝贵的象牙，对大象的非法狩猎，导致它们的后代无象牙的大象数量超出了平均数量。文章分析其中的生物学上的原因，因此文章内容是关于科学知识的。故选B项。