3.19帝都放狗~

zhangruic

真心累啊。。。这场遇见了一个妹纸很放松，lz超羡慕的，早晨进去心脏咚咚跳

数学：似乎JJ里木有的
1.某个公司的股票，special dividend是5 cents，在the first three quaters of the year发放；普通dividend是40 cents，在每个quarter发放。问本年度这个公司的股票收益（好像是这个词吧，LZ短路了）是多少？
选项中有 15/160  15/175 别的忘记了。。。
LZ读题时不知怎么想到了优先股。。。然后觉得股票不可能同时是优先股和普通股啊，然后开始转向。。。现在想想是想得太偏了ORZ。。答案应该是15/175吧大概。。。大概啊！
DS 2.某地的马匹用hand这个单位测量，然后1hand=4inches。给了一个换算示例：62inches=15.2hands（注意：这里60和15可能有错，但是2是不会错的。这个换算很奇怪吧，问题就在这）问一匹叫做M的马以inch算多高？
条件一：M是15.3hands（同样地，十分位上的3不会记错）
条件二：M介于另外两匹马高度之间。一匹15.2hands，一匹16hands。
lz很头大，这个换算好奇怪啊，然后不确定是不是直接把inches/4后的余数放到十分位上对不对，就认为条件一是NS了
条件二明显S。LZ纠结了半天选了B。。。这题应该定义为比较容易的题，因为是最后几个出来的，这几个都很简单，LZ忘了从哪个大牛的帖子里看到，粗线最后简单的情况说明Q已经被你征服了！！LZ正在暗爽中就遇到了这道题。。。题干还是有点长的，说不定LZ落下了某个关键条件呢。期待其他狗主补充哈~~

稍后补充其他部分。。。LZ实在是又累又饿

zhangruic

Verbal

被SC伤了。。。感觉一半多都考到了比较。LZ本来之前看了 http://forum.chasedream.com/GMAT_SC/thread-103101-1-1.html
讲比较的经典帖子，觉得很受用，之后训练中也没啥问题了，但是看来还木有掌握扎实吧，今天遇到的比较题看起来都那么奇怪的样子。。。现在已经忘了题目了，只能提醒一下大家看看比较这个知识点了！实在抱歉。。。

CR也不大顺，不过不顺惯了，反而觉得压力不大。有一道JJ里有的小朋友捡东西的题，是加强。选项是：
有一些行为能通过奖励加强
这个实验是在很多国家，很多小盆友身上做过的
实验还观察到，如果没有大人需要帮忙，小盆友们也是会捡掉在地上的东西
另外两个忘了。。。LZ左看右看选了MS很白痴第二个。。。

还有一道说的是通过奖励比通过惩罚来使人们做要求他们做的事情要有效（LZ举个例子，就是说让一个人守规矩好好表现，用奖励比惩罚强）。因为惩罚往往不能真正让人以后都这样做（举个例子，不能让他改变自己的坏习惯，他还会找机会不守规矩）。weaken
一个选项：得到奖励的人表面上按着做了，其实也不会永远这样。  LZ选了这个

还有一道题：实验给不同cultures的学生和老师们看照片，照片上是各种各样的expressions。实验结果发现，人们似乎对这些expressions的解释都差不多。于是科学家们得出结论：在世界上确实有这样一些expressions，不同cultures的人们对它们的理解是相同的。
weaken
一个选项：试验中对其他cultures不了解的人们，分别按照自己的culture对同一个expression做出了不同的解释。 LZ选了这个

RC 中了三篇： Commercial和involvement那个，JJ上很详细了。建议读一读，因为考的题似乎细节比较多。
纳斯卡线条。一个问题似乎JJ上木有：梯形线条trapezoid与什么有关？细节题。文中直接告诉与水flow的方向有关，但是选项中并没有直接这样表述的，大家到时定位原文后与选项仔细比较。
Lava JJ有比较详细，不难
还有一篇把LZ吓傻了，还以为粗事了：  OG13上米兰科维奇的冰期理论。。。回来发现OG上的文章只是提了M一下，不一样。没怎么读秒选的。第一段大概介绍了M说的variations in the Earth's orbit around the sun会导致的后果，比如冰期之类的。还有其他内容，没有读。第二段分两部分吧大概，先是说50年代随着碳14测定技术等的发展，科学家们陆续从调查中发现，M算的冰期时间与测算出来的不符，于是大家纷纷唾弃他。接着，随着科学技术的进一步精确，科学家们重新测算的冰期与Milankovitch cycle是相符的，于是大家纷纷开始赞成他。。。
题目有一道是：如果50年代的测算结果是正确的，那么会发生什么？（推断）
答案当然是科学家们那个时候就会赞成M了。。。  别的题目忘了，选的比较快

作文：某中心开了一家泳池，结果人就多了。这个中心准备再开multipurpose game room  gulf还是table tennis。author说，提供了这样一个range of activities 会带来竞争优势。与题库里的某题几乎一样。。。

IR：大部分是JJ上的，很详细，大家一定要看。在此感谢晨依MM了~
一道JJ里似乎没有的气泡图放在word里了。

大家加油哈~GMAT LZ木有报班（太坑。。。），然后自己找资料，大部分都是来自CD的。这次的成绩（Q51 V41）多亏了CD的指引和帮助！！！临考的JJ也起了很大作用，整理JJ的童鞋们辛苦啦~  希望LZ提供的这一点点东西能帮上大家

zhangruic

蓝柏

辛苦了！

大月威武

LZ立功了！

蓝柏

真心崇拜狗主超凡的记忆力！！！

米兰科维奇那篇 求确认~~


35 地球轨道变化对气候的影响[附考古+背景资料]
V1 by darkin_elf（700）
还有篇是说关于气候什么的：
以前有个研究者发现气候是根据地球orbiting的规律来的，就创立了一个学说，有另外一个研究者通过氧的测量证实了这个观点；第二段是说有第三的研究者跳出来说这个观点是不对的，因为他通过一个实验发觉某地和某地的研究数据表明是有variance的，最后一段那个用氧测量的研究者reconcile了这两个观点，说虽然是有orbiting的规律的，但是还是受到不同地质的影响的。
V2 by ilovesuri
开始认为orbit影响到地球的什么东东，第二段出来一个M学者，讲他的研究，第三段有W学者，研究同样的课题，但是见解不一样~
V3by rita324（650）
和og11上，第372页的内容很像的，讲的是ice age circle. 第一段说有一个叫M的人说和光的密度有关，这个后来才被普遍接受因为另 一个叫W的人在贝壳中发现了Oxygen物质。第二段说有一个叫I的人有别的理论，说ice age是ocean,ice sheet, atomsphere共同作用的结果。最后一段说，虽然W证实了M的观点是对的，可是他也说有共同作用的结果。。。汗。。。
V4 by icy421
地球轨道(应该是可是我觉得跟基金里所提的考古好像有点差异因为 没有提到冰川的layer)
P1陈述了M的理论然后因为当时实验条件不足的情况下并没有多少去 认可这个理论
P2 说有一个人提出了去美国一州做了地质研究结果发现他自己的理论不太对
P3结论就是M的理论其实是对的然后最后还是被接受

考古
V1
先是陈述了 这个理论 然后说当时人们只能在实验条件不足的情况下 大体的承认这个理论。但是1950年出了个A.B 研究了一些东西 carbon rating之类的，说是理论错误了。（我觉得这段时间内人们都不再接受M的理论了.随着科技的进步,应该是旧的改良结合很多其它新的technology出现了，证明了AB的 证据索取是比较片面的  M再次被人们接受。
问题：
1.  A..B. 对MilankovitchCycles Theory的看法导致一段时间内人们都不再接受M的理论了
2. 主题题：选的不同的方法对某一科学推断的研究和看法(没有一个选项提到了Milankovitch CyclesTheory,所以猜测某一科学推断指代Milankovitch CyclesTheory)。
3．Infer: 说如果第一段那些“当时人们”有accurate carbondating technologies 的时候，他们会怎样？
4. 新的学者（高亮了）对MilankovitchCycles Theory的看法
V2
某教授在1920S研究发现冰河期和地球轨道有关，然后是通过化石做了张表来说明。第二段突然说1950S科技进不了，发觉他理论不对了。然后1980S，科技有进步了，说其实1950S是不对的，以前那个教授其实是对的。
V3
P1：该理论的贡献
P2：该理论受到新的基于quantative和radiocarbon方法的挑战，被数据证实有误，但后来的研究证明上述方法有问题，新的更精确的方法验证了M理论的正确性，因而M理论重新得到认可
问题：1。 如果基于quantative和radiocarbon方法得到的结果是正确的，那会有什么结果。（答案都忘了，但此题不易解，干扰项严重）
V4
是change in earth orbit. 第一段讲M的理论多牛B，第二段讲50年代的什么试验证明M是错的，然后第二段的后半部分又说原来50年代的试验方法（还是数据？）是错误的，这样的话M的理论又被证明是对的了。
V5
然后还有一篇很长很长的是讲冰川的.第一段基本不考(大家大概扫扫好了,这文章有一屏半), 全是highlight的第二段.大意就是有一个专家提出了一个理论研究冰川的layer可以计算出时间还是什么的.第二段有人提出质疑,通过什么新的技术证明专家说的不对(有一个题目提到highlight的theorist起什么作用),但是1970年又有人重新做了research,发现其实质疑是错误的,于是还专家一个清白(有一道题目就是问1970年的研究做什么了,我觉得貌似应该是revise专家的提议).还有主旨题目.
V6
第一段：1920年，一个科学家M.M.（首字母）提出一个Claim/Theory说貌似地球的Orbit和Ice Age有关系。他的证据是在一些（可能是南北极的）冰川Layer里面发现了一些植物的标本。。
第二段：但是到了1950年，有一个根据CO2的研究指出M.M.的理论有问题，貌似指出问题的关键也是植物的标本问题。后来1970年研究技术更新之后，通过新技术表明，M.M.的理论还是可以被接受的~
V7
说M发现通过什么东西可以考证冰川的年代  而且这个东西受地球自转的影响。而且冰川会在世界各地周期性出现（澳大利亚除外，这里看似重要，但是没考）  后来第二段有科学家用新的 carbon dating技术推翻了他的结论，很多细节，完全没看懂，最后1970年以后一个什么技术的出现又还了M一个清白
V8
有一篇讲一个地质学家发现地球轨道会影响地球的气候，会使气候变冷，这个理论可以解释很多历史现象。但是1950年代的地质学家们发现用C测量一些化石的年龄，发现和上述理论相矛盾，说明上述理论错了，但1970年的地质学家们又发现1950年的测量不准确，那个理论是对的

注：在OG11和OG12中都有一篇阅读是关于Milankovitch理论的，但是并非此月的阅读原文，大家可以当背景资料阅读，我提供文章的开头关键句供大家查找：Milankovitch proposed in the early twentieth century that the ice ages were caused by variations in the Earth’s orbit around the Sun.   另外，看看下面的背景资料会对阅读有所帮助。

背景资料1
地球轨道根数变化与第四纪冰期 Changes of the Earth's Orbital Elements and the Quaternary Glacial Epoch
米兰柯维奇(Milankovitch)天文气候学理论和第四纪地质时期以来冰期的研究进展.研究结果表明,地球上的冰体积具有近10万yr的变化周期,并伴有近4万yr和2万yr的变化周期,它们是由于地球的轨道根数变化导致的气候变迁所致;不同的地球物理资料中均存在上述类似的变化周期,表明气候变迁所导致的变化是全球性效应,证实米兰柯维奇天文理论是基本正确的。他认为，北半球高纬夏季太阳辐射变化是驱动第四纪冰期旋回的主因。这个理论的核心是单一敏感区的触发驱动机制，即北半球高纬气候变化信号被放大、传输进而影响全球。最近，由于大量高分辨率及精确定年的气候变化记录的获得，从以下4个方面构成了对米氏理论的挑战：1）一些低纬地区并没有明显的10万年冰量周 期，而是以2万年岁差周期为主，表明北半球冰盖的扩张、收缩变化并没有完全控制低纬区的气候变化；2）在最近几次冰消期时，南半球和低纬区的温度增高，要 早于北半球冰盖的融化，表明冰消期的触发机制并非是北半球高纬夏季太阳辐射；3）大气CO2浓度在第2冰消期的增加同南极升温相一致，表明该时大气CO2 浓度增加亦有可能早于北半球冰盖消融；4）南半球的末次冰盛期有可能早于北半球。这就说明单一敏感区触发驱动机制已难以圆满解释所有观察事实，天文因素控 制下轨道尺度气候变化机制研究正面临理论突破的新需求和新机遇

背景资料2
At the recent American Geophysical Union meeting in San Francisco, the 25th anniversary of one of the great papers in paleoclimatology was celebrated. The paper, entitled “Variations in the Earth’s orbit: Pacemaker of the Ice Ages,” presented important new evidence supporting the orbital theory of glaciation. Orbital theory goes back over a century but is most closely associated with Milankovitch, who calculated the effects of gravitational perturbations on the seasonal cycle of Earth’s insolation (the radiation incident at the top of the atmosphere). Insolation varies on several time scales, including ~20,000 years (termed precession), ~40,000.

蓝柏

还有一个版本~~~


2.2.3.    ★研究地质时间**
V1 g20040636 & duke3d001 750
第一段 一个人M研究地球的climate和 和 orbit change之间是有关系的
可以用来推断地质时间   M的观点被很多人accept
第二段 出现了50年代的观点 科学家们开始采用碳标记 是反对M的 因为发现了一种动物 啥狗之类的 化石 它是在M推断的某一个climate不应该出现的。后来80年代新的科技又证明了M的观点是正确的。但是还有一个什么疑问 最后还是说支持 M的观点  
1 新时代的科学家同意的：我选的是A 50年代的科学家如果方法正确应该是要同意M观点的
结构：提出观点（支持），一些人质疑，后来又支持。

V2 zhaoyuangks 710 V34
关于地质的。结构是从1920年M的理论（P1）谈到1950年有科学家反驳再到1970年又反回来（P2）。
1 wingchu 760 有问1950年研究反驳的是M的什么理论，他认为是过去uplift导致weathering加快：选实践证明过去40年的uplift程度跟之前40年的差不多。
2 还有第二段的作用。

文言文 Golden已确认
V1 darkin_elf 700
还有篇是说关于气候什么的：
以前有个研究者发现气候是根据地球orbiting的规律来的，就创立了一个学说，有另外一个研究者通过氧的测量证实了这个观点；第二段是说有第三的研究者跳出来说这个观点是不对的，因为他通过一个实验发觉某地和某地的研究数据表明是有variance的，最后一段那个用氧测量的研究者reconcile了这两个观点，说虽然是有orbiting的规律的，但是还是受到不同地质的影响的。

V2 Golden 540 V14
第一段：1920年，一个科学家M.M.（首字母）提出一个Claim/Theory说貌似地球的Orbit和Ice Age有关系。他的证据是在（可能是南北极的）冰川Layer里面发现的一些植物的标本。
第二段：但是到了1950年，有一个根据CO2的研究指出M.M.的理论有问题，貌似指出问题的关键也是植物的标本问题。后来1970年研究技术更新之后，通过新技术表明，M.M.的理论还是可以被接受的~

V3
先是陈述了 这个理论 然后说当时人们只能在实验条件不足的情况下 大体的承认这个理论。但是1950年出了个A.B 研究了一些东西 carbon rating之类的，说是理论错误了。我觉得这段时间内人们都不再接受M的理论了.随着科技的进步,应该是旧的改良结合很多其它新的technology出现了，证明了AB的 证据索取是比较片面的  M再次被人们接受。
问题：
1.  A.B. 对Milankovitch Cycles Theory的看法导致一段时间内人们都不再接受M的理论了
2. 主题题：选的不同的方法对某一科学推断的研究和看法(没有一个选项提到了Milankovitch Cycles Theory,所以猜测某一科学推断指代Milankovitch Cycles Theory)。
3．Infer: 说如果第一段那些“当时人们”有accurate carbon-dating technologies 的时候，他们会怎样？
4. 新的学者（高亮了）对Milankovitch Cycles Theory的看法

V4
讲冰川. 第一段基本不考; 有一个题目提到highlight的theorist起什么作用, 还有一道题目就是问1970年的研究做什么了, 我觉得貌似应该是revise专家的提议. 还有主旨题目.

(疑似)原文未缩减 gitarrelieber
摘自Scientific American @ Jan 1990

The Yugoslav astronomer Milutin Milankovitch refined and formalized the hypothesis in the 1920’s and 1930’s.The astronomical pacemaker he advocated has three components, two that change the intensity of the seasons and a third that affects the interaction between the two driving factors. The first is the tilt of the earth’s spin axis. Currently about 23.5 degrees from the vertical, it fluctuates from 21.5 degrees to 24.5 degrees and back every 41,000 years. The greater the tilt is, the more intense seasons in both hemispheres become: summers get hotter and winter colder.

The second, weaker factor controlling seasonality is the shape of the earth’s orbit. Over a period of 100,000 years, the orbit stretches into a more eccentric ellipse and then grows more nearly circular again. As the orbital eccentricity increases, the difference in the earth’s distance from the sun at the orbit’s nearest and farthest points grows, intensifying the seasons in one hemisphere and moderating them in the other. (At present the earth reaches its farthest point during the Southern Hemisphere winter; as a result, southern winters are a little colder – than their northern counterparts.)

A third astronomical fluctuation governs the interplay between the tilt and eccentricity effects. It is the precession, or wobble, of the earth’s spin axis, which traces out a complete circle on the background of stars about every 23,000 years. The precession determines whether summer in a given hemisphere falls at near or a far point in the orbit– in other words, whether tilt seasonality is enhanced or weakened by distance sesonablity. When these two controllers of seasonality reinforce each other in one hemisphere, they oppose each other in the opposite hemisphere.

Milankovitch calculated that these three factors work together to vary the amount of sunshine reaching the high northern latitudes in summer over a range of some 20 percent – enough, he argued, to allow the great ice sheets that advanced across the northern continents to grow during intervals of cool summers and mild winters. For many years, however, the lack of an independent record of ice-age timing made the hypothesis untestable.

In the early 1950’s Cesare Emiliani produced the first complete record of the waxings and waning of past glaciations. It came from a seemingly odd place, the sea floor. Single-cell marine organisms called foraminifera house themselves in shells made of calcium carbonate. When the foraminifera die, sink to the bottom and contribute to these a-floor sediments, the carbonate of their shells preserves certain characteristics of the seawater they inhabited. In particular, the ratio of a heavy isotope of oxygen (oxygen 18) to ordinary oxygen (oxygen 16) in the carbonate preserves the ratio of the two oxygen atoms in the water molecules.

It is now understood that the ratio of oxygen isotopes in seawater closely tracks the proportion of the world’s water that is locked up in glaciers and ice sheets. A kind of meteorological distillation accounts for the link. Water molecules containing the heavier isotope tend to condense and fall as precipitation a tiny bit more readily than molecules containing the lighter isotope. Hence, as water evaporated from warm oceans moves away from the source, its oxygen 18 preferentially returns to the oceans in precipitation. What ultimately falls as snow on ice sheets and mountain glaciers is relatively depleted of oxygen 18. As the oxygen 18-poorice builds up, the oceans become relatively enriched in the isotope. The larger the ice sheets grow, the higher the proportion of oxygen 18 becomes in seawater – and hence in the sediments.

Analyzing cores drilled from seafloor sediments, Emiliani found that the isotopic ratio rose and fell in rough accord with the cycles Milankovitch had predicted. A chronology for the combined record showed in 1976 that the record contains the very same periodicities as the orbital process.

……

Others have found that during the last ice age the earth’s mountain glaciers also expanded. The evidence – from the heaps of debris plowed up by the glaciers, knows as moraines – is as clear in the tropics and the southern temperate latitudes. On all the mountains studied so far, regardless of geographic setting or precipitation rate, the snow line descended by about one kilometer, corresponding to a drop in temperature of about five degrees Celsius.

Where organic material was trapped in the moraines, radio carbon dating shows that the glaciers advanced and retreated on the same schedule. They fluctuated near their maximum extent between about 19,500 and 14,000 years ago, about the same time as the glaciations of northern ice sheets began to shrink, the mountain glaciers underwent a dramatic retreat that sharply reduced their size by about 12,500 years ago.

How could changes in summer sunshine at the latitude of Iceland have caused glaciers to grow and retreat in New Zealand and the southern Andes? If orbital cycles do indeed drive glacial cycles by acting directly on northern ice sheets, the response to seasonality changes in the high northern latitudes must be strong enough to override the effects of the very different changes in the Southern Hemisphere. One possibility is that the northern ice sheets themselves translate Northern Hemisphere seasonality into climatic change around the world.

蓝柏

...另一个。。。求狗主看一下这几个哪个和你考的内容更接近？


Milankovitch Cycles Theory
Milankovitch cycles theory is about the frequency of ice age. Milankovich proposed that the temperature of earth has something to do with the position of the earth in the orbit around sun. However it did not gain acceptance until 1968 when Dr. Imbrie presented additional evidence for M theory. He meassured the isotope level in small seashell deposit and the change of isotope abundancy corresponds with the temperature change.
However, later on, a geochemist tested the samples from Devil's Hole, a place in south Nevada and the results did not match with the previous results.
Even thought Dr. Imbrie still think M theory was valid, he conceded that many other factors contribute to the isotope level. It maybe why the results did not match.
OLD JJ
V1
是讲某人MM的理论，关于change in earth‘s orbit影响气候什么的，也没看懂……
V2
03/21 第二篇是change in earth orbit. 第一段讲M的理论多牛B，第二段讲50年代的什么试验证明M是错的，然后第二段的后半部分又说原来50年代的试验方法（还是数据？）是错误的，这样的话M的理论又被证明是对的了。
有益补充1：地球轨道根数变化与第四纪冰期 Changes of the Earth's Orbital Elements and the Quaternary Glacial Epoch
米兰柯维奇(Milankovitch)天文气候学理论和第四纪地质时期以来冰期的研究进展.研究结果表明,地球上的冰体积具有近10万yr的变化周期,并伴有近4万yr和2万yr的变化周期,它们是由于地球的轨道根数变化导致的气候变迁所致;不同的地球物理资料中均存在上述类似的变化周期,表明气候变迁所导致的变化是全球性效应,证实米兰柯维奇天文理论是基本正确的。 这个像不像jj里讲的mm理论？    冰川变化 地球轨道
有益补充2 （补充1的英文）：
At the recent American Geophysical Union meeting in San Francisco, the 25th anniversary of one of the great
papers in paleoclimatology was celebrated. The paper, entitled “Variations in the Earth’s orbit: Pacemaker
of the Ice Ages,” presented important new evidence supporting the orbital theory of glaciation. Orbital theory goes back over a century but is most closely associated with Milankovitch, who calculated the effects of gravitational perturbations on the seasonal cycle of Earth’s insolation (the radiation incident at the top of the atmosphere). Insolation varies on several time scales, including ~20,000 years (termed precession), ~40,000.
参考阅读
Can We Date the Ice Ages?
Following improvements in the ability to measure isotope ratios which came about as a spin-off of the wartime Manhattan project, physical chemist Harold Urey began to examine the possibility that the ratio of the two principal isotopes of oxygen found in the atmosphere might provide a clue as to past temperatures. It was based on the idea that the ratio of the heavier isotope (oxygen-18) to the more prevalent isotope (oxygen-16) found at the sea surface would change depending on the temperature of the ocean water near the surface. Urey thought that a careful study of the oxygen isotope ratio in the shells of sea creatures, which build their calcium carbonate shells from oxygen available in the seawater, might serve to indicate the temperature of the water in which they formed. During warmer periods, it was thought, evaporation from the ocean surface would tend to enrich the sea surface water with the heavier isotope of oxygen.
Perhaps, Urey reasoned, the isotope ratios found in the layers of discarded shells of sea organism which form the ocean bottom could thus serve as a record for the past temperatures of the ocean.
The theory is fraught with many ifs, but it was pursued with persistence, starting in the 1950s, by Italian-educated micropaleontologist Cesare Emiliani, a one-time collaboator of Urey at the Argonne Laboratory then associated with University of Chicago. Emiliani identified certain species of small shell-forming sea organisms known as foraminifera, which he thought suitable for oxygen-isotope analysis to determine past climates. The conclusions he drew as to the dating of the ice ages were constantly challenged by leading oceanographers, who found them in contradiction with their studies of ocean bottom cores. The method was also attacked on the grounds that it wasn't clear that the creatures formed their shells, known as tests, near enough to the surface to reflect changes in isotope ratios.
About 1968, a somewhat new interpretation of the oxygen isotope record was proposed by a young oceanographer and climatologist, Nicholas Shackleton, a Cambridge graduate and great nephew of the famous British Antarctic explorer of the same name. Shackleton proposed that the oxygen-isotope ratio could serve as a proxy, not for temperature but for sea level--the idea being that during periods of glacial advance, when a large volume of ocean water had been taken up into the continental ice sheets, the oxygen-18 ratios of the remaining water would consequently be higher. These might be detected in the foraminifera layers found in the ocean bottom cores. Again there are many ifs, but Shackleton examined isotopic ratios of snows in Alpine and Arctic regions as well as many other factors to bolster his hypothesis. In the 1970s a National Science Foundation-funded program of oceanographic studies, known as CLIMAP, collected a large number of sediment cores from different parts of the world ocean. The program, known as the Decade of the Oceans, was run in conjunction with some flawed statistical approaches to modeling of global atmospheric circulation that had originated in efforts of John von Neumann to use computer modeling for studies of weather modification. However, analysis of the oxygen isotopic ratios of foraminifera found in the undersea cores suggested to a team working at the Lamont-Doherty Geological Laboratory that there was a definite signal of 100,000 year cyclicity. Dr. John Imbrie, who ran the computer programs analyzing the data, was the first to hypothesize that the periodicities were caused by the Milankovitch orbital cycles.
A landmark paper by Hays, Imbrie and Shackleton, published in the December 1976 issue of Science magazine ("Variations in the Earth's Orbit: Pacemaker of the Ice Ages"), argued that the advance and retreat of the ice sheets was triggered by the changes in the Earth's orbital parameters. Other factors might also be present to reinforce these relatively small changes in solar radiation, but these were the pacemaker. By the theory of the orbital cycles, the evidence from the undersea cores explained that a major glaciation would be set off about every 100,000 years, followed by a short period known as an interglacial, a melt back lasting about 10,000 to 12,000 years. By the calculations of astronomers, the present interglacial, which has lasted about 11,000 years, is due to end any time. Indeed we have been in a period of long-term cooling for more than 6,000 years. The maximum summer temperature experienced in Europe over the last 10,000 years occurred about 6000 B.C. Over North America, where the process of glacial retreat lagged somewhat, the maximum was reached by about 4000 B.C. These estimates based on a vast array of evidence from geology, botany, and many other fields are consistent with the orbital theory of climate, for the northern hemisphere Summer would have been occurring at a point in Earth's orbit much nearer to the Sun than presently.
"One of the fundamental tenets of palaeoclimate modeling, the Milankovitch theory, is called into doubt by isotope analysis of a calcite vein, just reported in Science by Winograd and colleagues. The theory, which is backed up by a compelling bank of evidence, suggests that the ice ages determined, with unprecedented accuracy, in the new record cannot be reconciled with the planetary cyclicity. . .
Winograd and colleagues' evidence also turns on oxygen isotope data, this time from vein calcite coating the hanging wall of an extensional fault at Devils Hole, an aquifer in southern Nevada. In 1988, the authors published a date, 145,000 years, based on 234U-230Th dating for the end of the penultimate ice age (Termination II), marked by an increase in the 18O to 16O ratio, a change taken to mirror an increase in local precipitation. Although the date was only 17,000 year earlier than the previously accepted date of 128,000 years, if correct, this change is enough to bring Milankovitch mechanism into serious doubt. . .
I remain confused. The geochemist in me says that Devils Hole chronology is the best we have. And the palaeoclimatologist in me says that correlation between accepted marine chronology and Milankovitch cycles is just too convincing to be put aside. . .
One side will have to give, and maybe - just to be safe - climate modellers should start preparing themselves for a world without Milankovitch."

zhangruic

蓝柏MM    经过比较觉得
（1）大概和5L前4个无关
（2）5L此版本及以下几个版本应该就是我遇到的了。
“V1
先是陈述了 这个理论 然后说当时人们只能在实验条件不足的情况下 大体的承认这个理论。但是1950年出了个A.B 研究了一些东西 carbon rating之类的，说是理论错误了。（我觉得这段时间内人们都不再接受M的理论了.随着科技的进步,应该是旧的改良结合很多其它新的technology出现了，证明了AB的 证据索取是比较片面的  M再次被人们接受。
问题：
1.  A..B. 对MilankovitchCycles Theory的看法导致一段时间内人们都不再接受M的理论了
2. 主题题：选的不同的方法对某一科学推断的研究和看法(没有一个选项提到了Milankovitch CyclesTheory,所以猜测某一科学推断指代Milankovitch CyclesTheory)。
3．Infer: 说如果第一段那些“当时人们”有accurate carbondating technologies 的时候，他们会怎样？
4. 新的学者（高亮了）对MilankovitchCycles Theory的看法”

（3）6L的话，我不记得我读到过狗的化石。。。ORZ。。。补充的内容太像OG了，似乎不是。不过其他特点相符：分两大段，第二段是出题重点。  （7L应该差不多吧，描述比较少。。。）文章没有补充材料那么细致，提到特别多人名神马的，陈述证据的变化比较多。

大概就是这个样子。这篇阅读确实过得比较快，实在抱歉。。。

蓝柏

感激不尽！谢谢！