8.玛雅文明
V1说某种果树在玛雅废墟那块,长得很好,这个是玛雅文明的证明,但是有人反对,说是因为蝙蝠吃了果子排出种子才造成了这片果树林,和玛雅没有关系...但是后面又有证明说这片果林的产量是其他地方的果林的产量的2倍,说明还是玛雅文明的影响.
V2考古玛雅文明 说是什么玛雅人有什么珍贵的东西 但是后来证明这些东西是后人放的;但是最后又说和玛雅文明有关系。 感觉挺难的
V3 Maya遗址North和South地区在不同时间消失的原因，文章中貌似提到和South地区的地势更高，难以获取地下水有关;(好像托福文章)
Maya Water Problems
To understand the ancient Mayan people who lived in the area that is today southern Mexico and Central America and the ecological difficulties they faced, one must first consider their environment, which we think of as “jungle" or 'tropical rainforest." This view is inaccurate, and the reason proves to be important. Properly speaking, tropical rainforests grow in high-rainfall equatorial areas that remain wet or humid all year round. But the Maya homeland lies more than sixteen hundred kilometers from the equator, at latitudes 17 to 22 degrees north, in a habitat termed a “seasonal tropical forest." That is, while there does tend to be a rainy season from May to October, there is also a dry season from January through April. If one focuses on the wet months, one calls the Maya homeland a "seasonal tropical forest"; if one focuses on the dry months, one could instead describe it as a "seasonal desert.”
From north to south in the Yucatan Peninsula, where the Maya lived, rainfall ranges from 18 to 100 inches (457 to 2,540 millimeters) per year, and the soils become thicker, so that the southern peninsula was agriculturally more productive and supported denser populations. But rainfall in the Maya homeland is unpredictably variable between years; some recent years have had three or four times more rain than other years. As a result, modern farmers attempting to grow corn in the ancient Maya homelands have faced frequent crop failures, especially in the north. The ancient Maya were presumably more experienced and did better, but nevertheless they too must have faced risks of crop failures from droughts and hurricanes.
Although southem Maya areas received more rainfall than northern areas, problems of water were paradoxically more severe in the wet south. While that made things hard for ancient Maya living in the south, it has also made things hard for modem archaeologists who have difficulty understanding why ancient droughts caused bigger problems in the wet south than in the dry north. The likely explanation is that an area of underground freshwater underlies the Yucatan Peninsula, but surface elevation increases from north to south, so that as one moves south the land surface lies increasingly higher above the water table. In the northern peninsula the elevation is sufficiently low that the ancient Maya were able to reach the water table at deep sinkholes called cenotes, or at deep caves. In low-elevation north coastal areas without sinkholes, the Maya would have been able to get down to the water table by digging wells up to 75 feet (22 meters) deep. But much of the south lies too high above the water table for cenotes or wells to reach down to it. Making matters worse, most of the Yucatan Peninsula consists of karst, a porous sponge-like limestone terrain where rain runs straight into the ground and where little or no surface water remains available.
How did those dense southern Maya populations deal with the resulting water problem? It initially surprises us that many of their cities were not built next to the rivers but instead on high terrain in rolling uplands. The explanation is that the Maya excavated depressions, or modified natural depressions, and then plugged up leaks in the karst by plastering the bottoms of the depressions in order to create reservoirs, which collected rain from large plastered catchment basins and stored it for use in the dry season.For example, reservoirs at the Maya city of Tikal held enough water to meet the drinking water needs of about 10,000 people for a period of 18 months. At the city of Coba the Maya built dikes around a lake in order to raise its level and make their water supply more reliable. But the inhabitants of Tikal and other cities dependent on reservoirs for drinking water would still have been in deep trouble if 18 months passed without rain in a prolonged drought. A shorter drought in which they exhausted their stored food supplies might already have gotten them in deep trouble, because growing crops required rain rather than reservoirs.
9. 鹿背上的hamp(逻辑单题)
现有化石无法确定古代的一种鹿背上是不是humped。后来考古学家发现了一个洞窟里图片画了有hump的鹿，那么考虑到XXXX unmistakable，这是可信的。后来又说有人质疑这个画只是为了某种仪式ritual画的，不一定真实。但这是不足以担忧的，因为考古学家们发现洞里的其他画都非常写实。问的是这个提到XXXX unmistakable，和后面的这个洞里的其他画都写实分别有什么用，四个选项都是说的这两个句子用途不一样，而E是说他们都是结论 conclusion的证据。我选的E。
Which of following most logically completes the argument?
The last members of a now-extinct species of a European wild deer called the giant dear lived in Ireland about 16,000 years ago. Prehistoric cave paintings in France depict this animal as having a large hump on its back. Fossils of this animal, however, do not show any hump. Nevertheless, there is no reason to conclude that the cave paintings are therefore inaccurate in this regard, since ______.
A some prehistoric cave paintings in France also depict other animals as having a hump
B fossils of the giant deer are much more common in Ireland than in France
C animal humps are composed of fatty tissue, which dose not fossilize
D the cave paintings of the giant deer were painted well before 16,000 years ago
E only one currently existing species of deer has any anatomical feature that even remotely resembles a hump
10. Mystery of the Anasazi."
即使XXXX，某些人抛弃了XXX Mesa还是很puzzling.后来人们发现一种maize在人们住在这个mesa的后期变得很少，看来是食物原因。而且后来人们发现在这个后期一种喂养的火鸡的食用量55降到14，而野生动物食用增加。一开始我没留意到wild plant和wild animal的区别，题目都看晕。后来发现第一段讲的是crop第二段讲的是动物ORZ。
As the tourists prepare to depart Spruce Tree House, one asks Qumawunu the question that's on everyone's mind: Why, after having invested so much work in this place, did the ancestral Pueblo people leave it all behind?
The park ranger's answer sounds well-rehearsed: "We can come up with so many thoughts about why they moved in and why they moved out. But no one really knows for sure."
But it's a mystery that is finally beginning to unravel.
But while Crow Canyon has brought professional archaeology to the masses, it has yet to dismantle the biggest misconception about Mesa Verde's prehistory: that the ancestral Pueblo people simply vanished.
"I don't think we really ever thought that they just vanished into thin air," says Kuckelman. "I think the real enigma of the ancestral Pueblo people in the Mesa Verde region is, ŒWhy did they leave?'"
The ancestral Pueblo people didn't have a written language; no one left behind a detailed account of their last days in the Mesa Verde region. But Kuckelman believes that if she looks hard enough at places like Goodman Point Pueblo, she can find this story written on the walls -- and on the floors and in the trash heaps.
There's a partially excavated kiva, a subterranean dwelling near the northwest corner, that could hold part of the story. Standing over it, Kuckelman lifts the plywood covering that will protect the underground chamber over the winter and peers into the darkness. When this kiva was first excavated last summer, workers discovered prehistoric ash in the hearth and a rabbit skeleton nearby. Kuckelman thinks those findings may be the remains of one of the last meals ever eaten in the village.
She believes that when researchers dissolve the ash in liquid and analyze what remains, they'll find markedly little evidence of maize, compared to the amount of maize refuse in rubbish pits around the village. This isn't a wild guess. Kuckelman and her co-workers noticed the pattern when they ran similar tests at a nearby contemporary ruin, Sand Canyon Pueblo. These findings helped Kuckelman piece together a new theory about the ancestral Pueblo's departure, a theory she hopes to bolster with evidence from Goodman Point Pueblo and other excavations.
Kuckelman believes that as more and more people settled in the Mesa Verde region in the thirteenth century, they overwhelmed wild food sources in the area, such as deer and wild plants. As a result, they became increasingly dependent on maize crops -- not just for food, but for feed for domesticated turkeys -- as evidenced by the ubiquity of maize in refuse pits, essentially time capsules of the villagers' eating habits and customs. But then something wiped out their ability to cultivate their crops, as indicated by the limited maize remains in hearths. The rabbit skeleton may also be a clue, suggesting that turkey populations may have died out and forced these people to fall back on small wild game. This could mean that Kuckelman has found more than just evidence of the last meals ever eaten by the ancestral Pueblo people in the Mesa Verde region; she's found a possible impetus for their leaving: to search out new means of sustenance.
"The folks in this area had become very, very dependent on crops, like maize, and wild turkeys. Ultimately, I think that system backfired and collapsed on them," she says.
But why did the system backfire? Why did the entire population collapse? For a while, archaeologists thought they had the single answer: a great drought.
This idea was born from ancient wooden beams found in Mesa Verde ruins, beams whose tree rings captured the exact date and climate conditions of the prehistoric time period. Andrew E. Douglass, the father of tree-ring dating, studied these beams and, in a 1929 National Geographic article evocatively titled "The Secret of the Southwest Solved by Talkative Tree-rings," announced that he'd cleared up the mystery of the prehistoric migration. The beams, he wrote, showed evidence of a massive drought in the region from 1276 to 1299. Drought can be apocalyptic in the Mesa Verde region -- soil turns to powder, trees hold less moisture than kiln-dried wood -- and this one, it seemed, had led to a mass exodus.
Scholars are skeptical of single-factor explanations. Could one drought, no matter how devastating, be enough to depopulate an entire region? But for decades, no one had the hard evidence to challenge the drought theory. "Interpretations were kind of all over the board," says Kuckelman. That changed seventeen years ago, thanks to the work of a Ph.D. student named Carla Van West.
11. 彗星的pristine relics
关于宇宙里一些彗星的pristine relics, 新的研究表明因为接近太阳时温度太高，里面的relics很难测定。
The long-held perspective that comets are pristine remnants from the formation of the solar system has evolved from the prevailing views of 30 years ago, finds planetary scientist Dr. S. Alan Stern in a paper published in the journal Nature.
"It's fair to say that a sea change has taken place," says Stern, director of the Space Studies Department in the SwRI Space Science and Engineering Division. "We used to consider comets as wholly unchanged relics that had been stored ever since the era of solar system formation in a distant, cold, timeless deep freeze called the Oort cloud. We now appreciate that a variety of processes slowly modify comets during their storage there," he says. "As a result, it's become clear that the Oort cloud and its cousin the Kuiper Belt are not such perfect deep freezes."
The first evolutionary process to be recognized as affecting comets during their long storage was radiation damage, followed by the discovery that sandblasting from dust grains in the interstellar medium plays an important role. Next, researchers theorized that comets in the Oort cloud are heated to scientifically significant temperatures by passing stars and supernovae, says Stern. More recently, researchers are finding that comets in the Kuiper Belt are heavily damaged by collisions.
"It also now seems inevitable that most comets from the Kuiper Belt, though constructed of ancient material, cannot themselves be ancient -- instead they must be 'recently' created chips off larger Kuiper Belt Objects, formed as a result of violent impacts," says Stern. "This is truly a paradigm shift. Many of the short-period comets we see aren't even ancient!"
The classical view that comets do not evolve while they are stored far from the sun in the Oort cloud and Kuiper Belt began to change as far back as the 1970s, but the pace of discoveries about the way comets evolve picked up considerably in the 1980s and 1990s.
As a result of these findings, astronomers now better appreciate that comets, though still the most pristine bodies known, have been modified in several important ways since their birth, says Stern.
The realization that comets evolve during their long storage in the Oort cloud and Kuiper Belt provides insight and context to more confidently evaluate the results of astronomical and space mission observations of comets. So, too, it suggests that cometary sample return missions now on the drawing board for NASA should employ relatively deep subsurface sampling if truly pristine, ancient material is to be collected.