OG-32-198-205总结，8错5，痛定思痛！

kevinwww

上午做OG－32－198-205 错了5道，痛定思痛，总结如下：

第一段：新旧理论比较；第二段：老方法不再适用；第三段：新技术要求新理论；总结新理论及如何用。

第三段的后半段为重点，看懂可以作出198，200，201，203四题，就是因为没细看这句，做题时狂晕，结果是狂错！ 该半段总结如下：

“使用B可以帮助完成A，要想用上B必须找到C，C又依靠D模型，而D模型来自于E理论；所以E理论很重要！”

即：发现A <- 可以利用B <- 除非找到C <- C依靠D模型 <- D模型来自于E理论（所以E理论重要）

ABCDE分别是：
Find gold <- High-Tech <- Mineralized sites <- Conceptual Models <- Theory of ore-forming processes

faint 在考逻辑啊！看来不能有以前考虑TOEFL阅读的方式去做GMAT题了！再总结：

1. 阅读文章时一定要抓住文章的脉络（知道各段在讲什么及顺承关系），才不至于迷失在读不懂的单词和细节中；文章把握了脉络就可以做题了，碰到细节题在根据脉络回文中查找，比如199问具体的老理论，202问哪种gold更容易发现；

2.读文章时碰到作者逻辑推理的地方可以慢读，出题的可能性大。其他细节可以一带而过，如第三段前半段关于high-tech methods的6行都可以不看，结果也没出题，第一段也只需要知道有新旧两种理论就行了，具体的描述太专业了，很难看懂记住，碰到细节题时再回去查找就是了。

以上总结仅由这一篇文章而来，片面的地方还需通过以后的阅读纠正！

没总结每道题为什么我会选错，错的太多了

对地质和生物的文章比较头痛，第29篇也是狂错，希望多总结几篇此类的文章，能有所进步。

大家都怎么总结的呀？！

kevinwww

多谢版主的建议！

万事开头难，好好看看这些文章很有帮助，“走到正确的方向上，离成功也就不远了”！

wwwhahchn

这篇文章我做了14分钟，错了最后一题，还不是很明白

wwwhahchn

According to a recent theory, Archean-age gold-quartz

vein systems were formed over two billion years ago from

magmatic fluids that originated from molten granitelike

bodies deep beneath the surface of the Earth. This theory is

(5) contrary to the widely held view that the systems were

deposited from metamorphic fluids, that is, from fluids that

formed during the dehydration of wet sedimentary rocks.

he recently developed theory has considerable practical

importance. Most of the gold deposits discovered during

(10)the original gold rushes were exposed at the Earth’s surface

and were found because they had shed trails of alluvial

gold that were easily traced by simple prospecting methods.

Although these same methods still lead to an occasional

discovery, most deposits not yet discovered have gone

(15) undetected because they are buried and have no surface

expression.

The challenge in exploration is therefore to unravel the

subsurface geology of an area and pinpoint the position of

buried minerals. Methods widely used today include

(20) analysis of aerial images that yield a broad geological

overview; geophysical techniques that provide data on the

magnetic, electrical, and mineralogical properties of the

rocks being investigated; and sensitive chemical tests that

are able to detect the subtle chemical halos that often

(25) envelop mineralization. However, none of these high-

technology methods are of any value if the sites to which

they are applied have never mineralized, and to maximize

the chances of discovery the explorer must therefore pay

particular attention to selecting the ground formations most

(30) likely to be mineralized. Such ground selection relies to

varying degrees on conceptual models, which take into

account theoretical studies of relevant factors.

These models are constructed primarily from empirical

observations of known mineral deposits and from theories

35) of ore-forming processes. The explorer uses the models to

identify those geological features that are critical to the

formation of the mineralization being modeled, and then

tries to select areas for exploration that exhibit as many of

the critical features as possible.

205. It can be inferred from the passage that the efficiency of model-based gold exploration depends on which of the

following?

I. The closeness of the match between the geological features identified by the model as critical and the actual

geological features of a given area

II. The degree to which the model chosen relies on empirical observation of known mineral deposits rather than on

theories of ore-forming processes

III. The degree to which the model chosen is based on an accurate description of the events leading to

mineralization

(A) I only

(B) II only

(C) I and II only

(D) I and III only

(E) I, II and III

答案是D。哪位NN能给我解释一下为什么III也是对的呢？

wangyu73cn

这是OG的解释，简单分析一下：

205.

The best answer is D.

According to the passage, after constructing conceptual models based on observations of known mineral deposits and theories of ore-forming processes, “The explore uses the models to identify those geological features that are critical to the formation of the mineralization being modeled, and then tries to select areas for exploration that exhibit as many of the critical features as possible’ (lines 35-39).  

也就是说探矿大致分两步骤，一步是使用概念性模型确定地理特征，第二步是选择有这些地理特征的区域。其实这里还有一个预备步骤，即在观察已知矿层和成矿理论的基础上，建立概念性模型。

It can be inferred from this that the efficiency of the resulting exploration will depend on how closely the features of the selected area match the features identified by the model as critical (Statement I) and on how accurately the process of mineralization has been modeled (Statement III).  

第一论点对应着第一、二步骤，第二论点对应着预备步骤。

According to the passage, both empirical observations of known mineral deposits and theories of ore-forming processes are important in constructing the models, so Statement II cannot be part of the correct answer.

与文中内容相反。

rivergirl

类似这样的文章该运用啥策略呢? 一开始就精读而记住细节嘛? 我发现好些题目的考点都跳来跳去的, 要找准定位很难特别是时间紧的时候

tanlian

According to a recent theory, Archean-age gold-quartz

vein systems were formed over two billion years ago from

magmatic fluids that originated from molten granitelike

bodies deep beneath the surface of the Earth. This theory is

(5) contrary to the widely held view that the systems were

deposited from metamorphic fluids, that is, from fluids that

formed during the dehydration of wet sedimentary rocks.

he recently developed theory has considerable practical

importance. Most of the gold deposits discovered during

(10)the original gold rushes were exposed at the Earth’s surface

and were found because they had shed trails of alluvial

gold that were easily traced by simple prospecting methods.

Although these same methods still lead to an occasional

discovery, most deposits not yet discovered have gone

(15) undetected because they are buried and have no surface

expression.

The challenge in exploration is therefore to unravel the

subsurface geology of an area and pinpoint the position of

buried minerals. Methods widely used today include

(20) analysis of aerial images that yield a broad geological

overview; geophysical techniques that provide data on the

magnetic, electrical, and mineralogical properties of the

rocks being investigated; and sensitive chemical tests that

are able to detect the subtle chemical halos that often

(25) envelop mineralization. However, none of these high-

technology methods are of any value if the sites to which

they are applied have never mineralized, and to maximize

the chances of discovery the explorer must therefore pay

particular attention to selecting the ground formations most

(30) likely to be mineralized. Such ground selection relies to

varying degrees on conceptual models, which take into

account theoretical studies of relevant factors.

These models are constructed primarily from empirical

observations of known mineral deposits and from theories

35) of ore-forming processes. The explorer uses the models to

identify those geological features that are critical to the

formation of the mineralization being modeled, and then

tries to select areas for exploration that exhibit as many of

the critical features as possible.

这篇文章里面第一段讲的两种理论，我怎么老是觉得Archean-age gold-quartz vein systems是formed from magmatic fluids的，而后面他contrary to的widely held view 是systems were depsosited from metampophic fluids的呢？

所以做199题的时候，有点犯迷糊，

199. According to the passage, the widely held view of Archean- age gold-quartz vein systems is that such systems

(A) were formed from metamorphic fluids
(B) originated in molten granitelike bodies
(C) were formed from alluvial deposits
(D) generally have surface expression（A）
(E) are not discoverable through chemical tests

哪位nn来指点一下阿？

wangyu73cn

建议再读一下原文，搞清开头为新理论，后面5－6行为旧理论。

The best answer is a. In lines 5-6 the author mentions “the widely held view that the (Archean-age gold-quartz vein) systems were deposited from metamorphic fluids.” This view is said to be contrary to the recent theory that these systems originated in molten granitelike bodies, so choice B is not correct. Alluvial deposits are mentioned in the passage as having aided simple prospecting methods, but such deposits are not said to have formed that Archean-age gold-quartz vein systems (choice C). According to the author, “most deposits not yet discovered have gone undetected because they are buried and have no surface expression” (lines 14-16, so choice D is not correct. And choice E is incorrect because the author says that chemical tests can aid the discovery of gold deposits if they are conducted in areas where mineralization is likely to have taken place (lines 23-27).

swlfx

多谢王牛牛。

思谦

201.Which of the following statements about discoveries of

gold deposits is supported by information in the

passage ?

(A)The number of gold discoveries made  annually

has increased between the time of the original

gold rushes and the present.

(B)New discoveries of gold deposits are likely to be

the result of exploration techniques designed to

locate buried mineralization.

(C)It is umlikely that newly discovered gold deposits

will ever yield as much as did those deposits

discovered during the original gold rushes.

(D)Modern exp;orers are divvided onthe question of

the utility of simple prospecting methods as a

source of new discoveries of gold deposisits.

(E)Models based ont he theory that gold originated

from magmatic fluids ave already led to new

discoveries of gold deposits.

The best answer is B.According to the passage,"most [gold] deposits not yet discovered have gone undetected becousre they are vuried and hace no surffae expression"(line14-16);as a result,anexplorer uses conceptual models"to identify those geoogical features that are citical to the formation of the nieralization being modeled, and then tries to select areas for exploration"(lines 35-38).The passage provides no information abou the number of gold dicoveries or the yielde of gold deposites past or present ,so choices A and C are not correct.The author dies not suggest that ther e is any disagreement concerning the utility of simple prospeddting methods  ,which the author says only occasionally lead to new discoveries,so choice D is incorrect.And although the  author indicates that the theory that gold originated,there is no information in the passage indicating that models based on this theory have alreadu led to new discoveries of gold deposits  ,so choice E is incorrect.

(B)New discoveries of gold deposits are likely to be the result of wxploration techniques designed to locate buried mineralization.

这题为什么选B呀?

205. It can be inferred from the passage that the efficiency of model-based gold exploration depends on which of the following?

I. The closeness of the match between the geological features identified by the model as critical and the actual

geological features of a given area

II. The degree to which the model chosen relies on empirical observation of known mineral deposits rather than on

theories of ore-forming processes

III. The degree to which the model chosen is based on an accurate description of the events leading to

mineralization

(A) I only

(B) II only

(C) I and II only

(D) I and III only

(E) I, II and III

答案是D。哪位NN能给我解释一下为什么III也是对的呢？（和4楼的一样的问题，不好意思，5楼的解释我不是很明白，我在文中没找到og解释中的on how accurately the process of mineralization has been modeled ）

[此贴子已经被作者于2005-7-25 22:39:33编辑过]