11．A recent finding has showed that blue-eyed people have already been living in Europe for at least 7，000years．
A man who lived on the Iberian Peninsula before Europeans became farmers probably had blue eyes but dark hair and skin，according to scientists who have arranged his DNA in order．This surprising combination of eye，hair and skin coloring may not have been unusual during his lifetime，but it is no longer seen among modem Europeans，reported by the journal Nature．
The man，a Neolithic hunter-gatherer known to scientists as La BranaⅠ，is of great interest to scientists because he offers a brief introduction to what was in Europeans'DNA before agriculture spread through the continent．Experts have theorized that certain genetic feature spread quickly among humans after they adopted the farming lifestyle．La BranaⅠshows that at least some of their predictions were correct．
The man's skeleton，along with that of a male companion，was discovered in 2006in a cave in what is now northeastern Spain．The site，known as La Brana-Arintero，sits about 5，000feet above sea level，and the cave provided a cold，refrigerator-like environment that preserved his DNA．
In the lab，scientists were able to remove enough DNA from a single tooth to reconstruct La BranaⅠ's entire genome （基因组）．They compared it to the DNA of other ancient Europeans（including Otzi，the 5，300-year-old mummy found in an Alpine glacier） and determined that he was a closer match with hunter-gatherers than with farmers．
When it came to genes that would influence La BranaⅠ's appearance，the researchers found that their 7，000-year-old subject had versions of two skin pigment（色素） genes that are either very rare or nonexistent among Europeans today．Then they looked at other places in the genome that influence pigmentation（色素沉着）and found a mix of ancient and modern gene variants（变种）．Taken together，La BranaⅠ's DNA"is likely to have resulted in dark skin pigmentation and dark or brown hair，"they wrote．
However，his DNA indicates that his eyes were most likely blue，the scientists found．This suggests that gene variants for light-colored eyes and skin did not spread together，they wrote，adding that La BranaⅠ's combination"of dark skin and non-brown eyes is unique and no longer present in contemporary European populations．"Today，a blue-eyed person would typically have fair skin．To get some idea of whether La BranaⅠ's coloring was unusual for his day，the researchers will try to arrange in order the DNA of his companion，who has been named La BranaⅡ．
32．Scientists have carried out the research into La BranaⅠbecause they wanted to know
C．
A．today's Europeans'DNA
B．the ancient agriculture in Europe．
C．European hunter-gatherers'DNA．
D．the correctness of some of their predictions
33．La BranaⅠ's skeleton was best preserved mainly because ofB．
A．the height of the cave
B．the cold condition in the cave
C．the location of the cave
D．the wet condition in the cave
34．Which of the following statements is TRUE？B
A．La BranaⅠ's gene variants spread together．
B．La BranaⅠ's DNA influences his appearance．
C．Today's blue-eyed person may typically have rough rather than fair skin．
D．La BranaⅠ's gene is completely different from the contemporary Europeans'．
35．The last paragraph suggests thatC．
A．La BranaⅡhas the same genome with La BranaⅠ．
B．Blue-eyed people were common in Europe 7，000years ago．
C．It's not certain that La Brana's appearance was common at that time．
D．BranaⅠ's combination of dark skin and non-brown is popular in contemporary Europeans．
分析 本文属于说明文阅读，作者通过这篇文章主要向我们介绍了最近关于 La BranaⅠ的调查，事实证明这个群体的基因已经存在了七千多年，但是这个基因并没有广泛存在，蓝眼睛的人在欧洲依然很少．
解答 32．C 细节理解题，根据第三段The man，a Neolithic hunter-gatherer known to scientists as La BranaⅠ，is of great interest to scientists because he offers a brief introduction to what was in Europeans'DNA before agriculture spread through the continent．可知科学家们研究 La BranaⅠ是因为他们想知道欧洲猎人的DNA，故选C．
33．B 细节理解题题，根据第四段The site，known as La Brana-Arintero，sits about 5，000feet above sea level，and the cave provided a cold，refrigerator-like environment that preserved his DNA．可知La BranaⅠ的骨架保存最好的主要原因是因为洞里的寒冷条件，故选B．
34．B 推理判断题，根据第六段Taken together，La BranaⅠ's DNA"is likely to have resulted in dark skin pigmentation and dark or brown hair，"they wrote．可知La BranaⅠ的基因可能导致黑皮肤色素沉着，以及黑色或棕色的头发，因此可推断出它能影响人们的外表，故选B．
35．C 推理判断题，根据最后一段This suggests that gene variants for light-colored eyes and skin did not spread together，they wrote，adding that La BranaⅠ's combination"of dark skin and non-brown eyes is unique and no longer present in contemporary European populations．"Today，a blue-eyed person would typically have fair skin．可知La Brana的外表并不是常见的，故选C．
点评 考查学生的细节理解和推理判断能力．做细节理解题时一定要找到文章中的原句，和题干进行比较，再做出正确选择．在做推理判断题时不要以个人的主观想象代替文章的事实，要根据文章事实进行合乎逻辑的推理判断．
