Question

A“lost tribe”that reached America from Australia may have been the first Native Americans,according to a new theory． 　　If proved by DNA evidence,the theory will break long established belief about the southerly migration of people who entered America across the Bering Strait,found it empty and occupied it． 　　On this theory rests the belief of Native Americans to have been the first true Americans．They would be classified to the ranks of escapee,beaten to the New World by Aboriginals（土著人）in boats． 　　To a European,this may seem like an academic argument,but to Americans,it is a philosophical question about identity（身份）,Silvia Gonzales,of Liverpool University said． 　　Her claims are based on skeletons found in the California Peninsula of Mexico that have skulls（头骨）quite unlike the broad Mongolian features of Native Americans．These narrow— skulled people have more in common with southern Asians,Aboriginal Australians and people of the South Pacific Region． 　　The bones,stored at the National Museum of Anthropology（人类学）in Mexico City,have been carbon— dated and one is 12,700 years old,which placed it several thousand years before the arrival of people from the North．“We think there were several migration waves into America at different times by different human groups,”Dr．Gonzales said．“The timing,route and point of origin of the first colonization of America remains a most contentious topic in human evolution．” 　　But comparisons based on skull shape are not considered conclusive by anthropologists,so a team of Mexican and British scientists,backed by the Natural Environment Research Council,has also attempted to take out DNA from the bones．Dr．Gonzales declined yesterday to say exactly what the results were,as they need to be checked,but indicated that they were consistent（一致）with an Australian origin． (1) It is generally considered that the first Native Americans came from ________ [　　] A． North Asia B． Australia C． South Pacific D． South Asia (2) The skeletons found in the California Peninsula of Mexico have ________ [　　] A． the broad skull shape B． the narrow skull shape C． different features of Aboriginal Australians D． the same features of Native Americans (3) The underlined“contentious”is similar in meaning to“________” [　　] A． likely to cause great interest B． difficult to solve C． well-known to all D． likely to cause argument (4) Which of the following statements is true according to the text? [　　] A． Research on skulls can draw an exact conclusion． B． DNA tests have proved the fact that the first Native Americans came from Australia． C． Scientists are still not sure about the origin of the Native Americans． D． People began to enter America across the Bering Strait about 12,700 years ago．

Answer 1

答案：1．A;2．B;3．D;4．C;
解析：

(1)	推断题。第二段的意思是“如果DNA检测证实了这个理论的话，这将动摇长期以来人们一直坚信的观点：一群往南迁徙的移民穿过白令海峡进入美洲后，发现无人在此居住，便占领了它”，据此推断可得。
(2)	细节题。根据第五段表述的意思“这些头骨和美国土著居民那种宽头骨的特征极为不同。这些窄头骨的人种和南亚人、澳洲土著人和环南太平洋地区国家的人种有更多共同点”可知。
(3)	词义猜测题。科学家一直在探讨“谁是美洲最早的土著居民”这一问题，根据上下文可猜测出，在人类进化史上，最早在美国进行殖民活动的时间、路线和人口来源是一个最“具争议性的”话题。
(4)	事实确认题。本文提到的“新理论”和“长期以来人们一直坚信的观点”都在探讨、研究之中。对于DNA检测，冈萨雷斯博士拒绝透露确切的结果，因为研究结果还需要核实，他只是暗示这些DNA和澳大利亚人的血统是吻合的。由此可知C是正确的。