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
高二英语试题 第4页（共10页） 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.
26. How does the writer draw readers' attention to the topic?
A. By comparing ^gures. B. By offering explanation.
C. By giving an example. D. By introducing an expert.
27. What might be the reason for the increase of tuskless females?
A. Illegal hunting. B. Pure coincidence.
C. Natural evolution. D. Effective protection.
28. What does the underlined word “slaughtered” in Paragraph 3 mean?
A. Raised. B. Protected. C. Killed. D. Trained.
29. 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.
30. In which section of a newspaper may this text appear?
A.Health. B. Science. C. Education. D. Finance.

26~30 AACDB