44. D。 事实细节题。由第二段第二句“By then, the Inca people were already living in South America ...”可知the Inca people在玻利尼西亚人到达南美洲之前，已经在那里居住了。

43. B。　 事实细节题。由文章倒数第三段“The researchers also compared the genetic material, or DNA, from the South American chicken bone with DNA from 11 chicken bones that had been found on the Polynesian islands of Tonga and American Samoa.”和倒数第二段可知科学家是通过对两地挖出的鸡骨进行DNA鉴定发现这个结果的。

42. D。 事实细节题。由文章第二段可知第一批从Polynesia到Chile的人是在大约620年前，而根据第二段最后一句可知，第一批欧洲人晚了大约一个世纪，因此他们是约在520年前到的南美洲的。

41. D。 主旨大意题。本文在第一段点题，根据第一段第四句“When it comes to the trip between Polynesia and South America, chickens may have been among the first ocean voyagers, according to new evidence.”并根据后面科学家对在玻利尼西亚群岛和南美洲挖出的鸡骨进行DNA鉴定等，可知D选项正确。

45. Why was it difficult for people to travel across the oceans in ancient times, according to the passage?

　　 1) It was difficult to take many chickens as food.

　　 2) People had difficulty making careful and detailed sailing plans.

　　 3) People lacked maps and the knowledge of weather forecasting.

　　 4) People had to make boats by hand.

　　 5) It took great determination to cross an ocean.

　 A. 1) 4) 5)　　 B. 2) 3) 4)　 C. 2) 4) 5)　　 D. 1) 2) 3)　　　　　　　　　　　　

答案：

　　 现在飞越海洋是一件轻而易举的事情，然而几个世纪以前渡过海洋需要周密的计划、人造船只和勇气。是谁最先渡过了哪个海洋一直是科学家和历史学家研究的话题，最近研究结果发现鸡可能也是最早渡过玻利尼西亚和南美之间的海洋的。

44. What do we learn from the passage?

　　 A. European explorers and their chickens were the first to sail to South America.

　　 B. Chickens in South America have the same ancestors as those in Polynesia.

　　 C. In ancient times, a 6,000-mile channel separated Polynesia from South America.

　　 D. Before the Polynesians arrived in South America, the Inca people had lived there. '

43. People found that chickens were among the first to travel from Polynesia to South America by ___________.

　　 A. comparing the colors of eggs laid by chickens from the two places

　　 B. comparing the DNA of chicken bones dug up on the Polynesian islands and that of the chicken bones from South America

　　 C. studying some previous theories

　　 D. asking the natives of South America

42. When did the first European explorers reach South America?

　　 A. About 620 years ago.　 　　　 B. About 2.000 years ago.

　　 C. About 600 years ago.　 　　　 D. About 520 years ago.

41. What is the passage mainly about?

　　 A. It was difficult for ancient people to travel between Polynesia and South America.

　　 B. The first people who lived in Chile and Polynesia.

　　 C. Valuable chicken bones have been found in Chile.

　　 D. Chickens -- the first to travel between Polynesia and South America.