babypace暂别G

annwangwangqxwz

我也在做GWD,觉得gwd的文章和题目都要比og难，易混淆，绕。建议是继续做gwd阅读，最后复习总结。这是我这两天的心得。

建议只做参考，因为我的gwd正确率不高，希望不会误导。

babypace

嗯，是要总结再看的。如果考试遇到ＧＷＤ阅读，自己又记不得的，肯定懊悔死了。

努力看。。。发现大老鼠的阅读方法，觉得能用。我也来快速读一遍，把握大结构，然后在做题时回去定位。

郁闷的是钻石那篇，我一点没看明白呀！

babypace

看了ＯＧ阅读开篇，感觉有点帮助。

ＯＧ阅读做得感觉还是不好。希望在看完ＥＴＳ的出题方向后，会有所提高。

ＸＹＧＷＤ５

继续错１２个。我觉得除非阅读和SC再有突破，否则，11，12个就是我目前的水平了，继续做还是一样的。

caesar2005

快速阅读，我用的是另外一个nn的精读，每次都仔细看文章，尽量不回去定位。话说回来，这么看，基本上是不错题的，但是不知道自己到底水平如何，郁闷。

baby mm加油啊

携隐

我二战是基本不回去定位的。

baby，钻石那篇我觉得是很好的文章，一定要弄清楚。弄清楚了那篇，GWD阅读没有更难的了。GWD里面还有一些相似背景的文章，看完了钻石，基本其他的都可以顺带一起理解的。

有时间不如贴出来大家一起看看。

babypace

谢谢XY，我下午在办公室就把它贴出来，希望大家能帮助我一起看看。阅读不提高，我不可能控制8个以下。SC虽然也有问题，但是感觉自己还能复习，阅读就没有头脑了。

babypace

      Diamonds are almost impos-

            sible to detect directly because they

            are so rare:  very rich kimberlite

Line     pipes, the routes through which

  (5)      diamonds rise, may contain only

three carats of diamonds per ton

of kimberlite.  Kimberlite begins as

magma in Earth’s mantle (the layer

between the crust and the core).  As

(10)     the magma smashes through layers

of rock, it rips out debris, creating

a mix of liquid and solid material.

Some of the solid material it brings

up may come from a so-called

(15)     diamond-stability field, where condi-

tions of pressure and temperature

are conducive to the formation of

diamonds.  If diamonds are to sur-

vive, though, they must shoot toward

(20)     Earth’s surface quickly.  Otherwise,

            they revert to graphite or burn.

            Explorers seeking diamonds look

for specks of “indicator minerals”

peculiar to the mantle but carried up

(25)     in greater quantities than diamonds

and eroded out of kimberlite pipes

into the surrounding land.  The stan-

dard ones are garnets, chromites,

and ilmenites.  One can spend years

(30)     searching for indicators and tracing

them back to the pipes that are their

source; however, 90 percent of

            kimberlite pipes found this way are

barren of diamonds, and the rest

(35)    are usually too sparse to mine.

      In the 1970’s the process of

locating profitable pipes was refined

by focusing on the subtle differ-

ences between the chemical

(40)    signatures of indicator minerals

found in diamond-rich pipes as

opposed to those found in barren

pipes.  For example, G10 garnets,

a type of garnet typically found in

(45)     diamond-rich pipes, are lower in

calcium and higher in chrome than

garnets from barren pipes.  Geo-

chemists John Gurney showed that

garnets with this composition were

(50)     formed only in the diamond-stability

field; more commonly found ver-

sions came from elsewhere in the

mantle.  Gurney also found that

though ilmenites did not form in the

(55)     diamond-stability field, there was a

link useful for prospectors:  when

the iron in ilmenite was highly

oxidized, its source pipe rarely

contained any diamonds.  He rea-

(60)     soned that iron took on more or less

oxygen in response to conditions in

the kimberlitic magma itself—mainly

in response to heat and the avail-

able oxygen.  When iron became

(65)     highly oxidized, so did diamonds;

that is, they vaporized into carbon

dioxide.

Q23:

The primary purpose of the passage is to

                        

discuss an objection to Gurney’s theories about the uses of indicator minerals

explore the formation of diamonds and the reasons for their scarcity

analyze the importance of kimberlite pipes in the formation of diamonds

define the characteristics of indicator minerals under differing conditions

explain a method of determining whether kimberlite pipes are likely to contain diamonds

Answer:

--------------------------------------------------------------------------------

Q24:

Each of the following is mentioned in the passage as a difference between G10 garnet and other versions of garnet EXCEPT

                        

level of oxidation

commonness of occurrence

chemical signature

place of formation

appearance in conjunction with diamonds

Answer:

--------------------------------------------------------------------------------

Q25:

The passage suggests that the presence of G10 garnet in a kimberlite pipe indicates that

                        

the pipe in which the garnet is found has a 90% chance of containing diamonds

the levels of calcium and chrome in the pipe are conducive to diamond formation

the pipe passed through a diamond-stability field and thus may contain diamonds

any diamonds the pipe contains would not have come from the diamond-stability field

the pipe’s temperature was so high that it oxidized any diamonds the pipe might have contained

Answer:

--------------------------------------------------------------------------------

Q26:

According to the passage, Gurney refined the use of ilmenites in prospecting for diamonds in which of the following ways?

He found that ilmenites are brought up from the mantle by kimberlite pipes and erode out into the surrounding land in greater quantities than diamonds.

He found that since ilmenites do not form in the diamond-stability field, their presence indicates the absence of diamonds.

He showed that highly oxidized iron content in ilmenites indicates a low survival rate for diamonds.

He found that when the iron in ilmenites is highly oxidized, conditions in the magma were probably conducive to the formation of diamonds.

He showed that ilmenites take on more or less oxygen in the kimberlite pipe depending on the concentration of diamonds.

Answer:

钻石这篇我贴出来了。我自己再重新看一遍，争取能看出点名堂来。至少看出文章思路，作者中心观点等。

[此贴子已经被作者于2005-8-27 2:00:52编辑过]

babypace

第二遍看这篇文章，心平气和地看，感觉突然清晰。或许我大脑比较清晰的时间是下午，不是晚上。而且，我感觉我最弱的不该是科技类文章，而是文科类的文章。

现把第二遍的理解和解题写下来。大家帮助我一起看看。

Diamonds are almost impos-(作者开篇观点：钻石很难直接发现，因为它们发现稀有)

            sible to detect directly because they

            are so rare:  very rich kimberlite

Line     pipes, the routes through which

  (5)      diamonds rise, may contain only

three carats of diamonds per ton

of kimberlite.（解释为什么说钻石是稀有的）

            Kimberlite begins as magma in Earth’s mantle (the layer

between the crust and the core).  As

(10)     the magma smashes through layers

of rock, it rips out debris, creating

a mix of liquid and solid material.

Some of the solid material it brings

up may come from a so-called

(15)     diamond-stability field, where condi-

tions of pressure and temperature

are conducive to the formation of

diamonds.  If diamonds are to sur-

vive, though, they must shoot toward

(20)     Earth’s surface quickly.  Otherwise,

            they revert to graphite or burn.

            Explorers seeking diamonds look

for specks of “indicator minerals”

peculiar to the mantle but carried up

(25)     in greater quantities than diamonds

and eroded out of kimberlite pipes

into the surrounding land.  The stan-

dard ones are garnets, chromites,

and ilmenites.  One can spend years

(30)     searching for indicators and tracing

them back to the pipes that are their

source; however, 90 percent of

            kimberlite pipes found this way are

barren of diamonds, and the rest

(35)    are usually too sparse to mine. （以上都在说明kimberlite pipe和钻石的关系：如何判断有无钻石，钻石很少）

      In the 1970’s the process of

locating profitable pipes was refined

by focusing on the subtle differ-

ences between the chemical

(40)    signatures of indicator minerals

found in diamond-rich pipes as

opposed to those found in barren

pipes.  For example, G10 garnets,

a type of garnet typically found in

(45)     diamond-rich pipes, are lower in

calcium and higher in chrome than

garnets from barren pipes.  Geo-

chemists John Gurney showed that

garnets with this composition were

(50)     formed only in the diamond-stability

field; more commonly found ver-

sions came from elsewhere in the

mantle.  （新方法来更准确定位钻石的存在，用G10 Garnets的特殊化学结构来定位钻石）Gurney also found that

though ilmenites did not form in the

(55)     diamond-stability field, there was a

link useful for prospectors:  when

the iron in ilmenite was highly

oxidized, its source pipe rarely

contained any diamonds.  He rea-

(60)     soned that iron took on more or less

oxygen in response to conditions in

the kimberlitic magma itself—mainly

in response to heat and the avail-

able oxygen.  When iron became

(65)     highly oxidized, so did diamonds;

that is, they vaporized into carbon

dioxide.（用ilmenites来定位钻石是另一个方法：在ilmenites里面高度氧化的铁元素预示着那个kimberlite pipe的钻石也会由于高温而蒸发为二氧化碳）

Q23:

The primary purpose of the passage is to

（我觉得文章主要是说如何发现kimberlite pipe里面是否有钻石）                    

1. discuss an objection to Gurney’s theories about the uses of indicator minerals


2. explore the formation of diamonds and the reasons for their scarcity （只在第一段开头说了钻石的形成和稀有。后面主要都在讲为什么稀有：是因为钻石很难被勘测。所以此选项不够全面概括全文内容，错了）


3. analyze the importance of kimberlite pipes in the formation of diamonds


4. define the characteristics of indicator minerals under differing conditions


5. explain a method of determining whether kimberlite pipes are likely to contain diamonds

Answer: E

--------------------------------------------------------------------------------

Q24:

Each of the following is mentioned in the passage as a difference between G10 garnet and other versions of garnet EXCEPT

（这题比较简单，level of oxidation是ilmenites的特征）               

1. level of oxidation


2. commonness of occurrence


3. chemical signature


4. place of formation


5. appearance in conjunction with diamonds

Answer: A

--------------------------------------------------------------------------------

Q25:

The passage suggests that the presence of G10 garnet in a kimberlite pipe indicates that

                        

1. the pipe in which the garnet is found has a 90% chance of containing diamonds


2. the levels of calcium and chrome in the pipe are conducive to diamond formation （这个没有在文章中直接state，但是文章suggest了有低钙高铬G10  garnet的环境下，通常有diamond，所以是否有diamond可以通过钙和铬的含量来判断）


3. the pipe passed through a diamond-stability field and thus may contain diamonds （我看到有人讨论B和C，我觉得C不对。理由是pass through diamond-stability field的pipe不是造成是diamond的原因，而且和是否有G10 garnet没有直接联系。G10 garnet的主要作用在于，富有diamond的pipe里面的G10 garnet通常是低钙，高铬的，用来反推出那个pipe是否有diamond。 C这个答案没有直接回答presence of G10 garnet in kimberlite pipe indicates what的问题，所以我认为不对。）



4. any diamonds the pipe contains would not have come from the diamond-stability field



5. the pipe’s temperature was so high that it oxidized any diamonds the pipe might have contained

Answer: B

--------------------------------------------------------------------------------

Q26:

According to the passage, Gurney refined the use of ilmenites in prospecting for diamonds in which of the following ways?

（这题也比较简单，C是答案）

1. He found that ilmenites are brought up from the mantle by kimberlite pipes and erode out into the surrounding land in greater quantities than diamonds.


2. He found that since ilmenites do not form in the diamond-stability field, their presence indicates the absence of diamonds.


3. He showed that highly oxidized iron content in ilmenites indicates a low survival rate for diamonds.


4. He found that when the iron in ilmenites is highly oxidized, conditions in the magma were probably conducive to the formation of diamonds.


5. He showed that ilmenites take on more or less oxygen in the kimberlite pipe depending on the concentration of diamonds.

Answer: C

babypace

A meteor stream is composed of dust particles that have been ejected from a parent comet at a variety of velocities. These particles follow the same orbit as the parent comet, but due to their differing velocities they slowly gain on or fall behind the disintegrating comet until a shroud of dust surrounds the entire cemetery orbit. Astronomers have hypothesized that a meteor stream should broaden with time as the dust particles’ individual orbits are perturbed by planetary gravitational fields. A recent computer-modeling experiment tested this hypothesis by tracking the influence of planetary gravitation over a projected 5,000-year period on the positions of a group of hypothetical dust particles. In the model, the particles were randomly distributed throughout a computer simulation of the orbit of an actual meteor stream, the Geminid. The researcher found, as expected, that the computer-model stream broadened with time. Conventional theories, however, predicted that the distribution of particles would be increasingly dense toward the center of a meteor stream. Surprisingly, the computer-model meteor stream gradually came to resemble a thick-walled, hollow pipe.

Whenever the Earth passes through a meteor stream, a meteor shower occurs. Moving at a little over 1,500,000 miles per day around its orbit, the Earth would take, on average, just over a day to cross the hollow, computer-model Geminid stream if the stream were 5,000 years old. Two brief periods of peak meteor activity during the shower would be observed, one as the Earth entered the thick-walled “pipe” and one as it exited. There is no reason why the Earth should always pass through the stream’s exact center, so the time interval between the two bursts of activity would vary from one year to the next.

Has the predicted twin-peaked activity been observed for the actual yearly Geminid meteor shower? The Geminid data between 1970 and 1979 show just such a bifurcation, a secondary burst of meteor activity being clearly visible at an average of 19 hours (1,200,000 miles) after the first burst. The time intervals between the bursts suggest the actual Geminid stream is about 3,000 years old.

80. The primary focus of the passage is on which of the following?

1. Comparing two scientific theories and contrasting the predictions that each would make concerning a natural phenomenon

B.       Describing a new theoretical model and noting that it explains the nature of observations made of a particular natural phenomenon

3. Evaluating the results of a particular scientific experiment and suggesting further areas for research



4. Explaining how two different natural phenomena are related and demonstrating a way to measure them



5. Analyzing recent data derived from observations of an actual phenomenon and constructing a model to explain the data

81. According to the passage, which of the following is an accurate statement concerning meteor streams?

1. Meteor streams and comets start out with similar orbits, but only those of meteor streams are perturbed by planetary gravitation.



2. Meteor streams grow as dust particles are attracted by the gravitational fields of comets.



3. Meteor streams are composed of dust particles derived from comets.



4. Comets may be composed of several kinds of materials, while meteor streams consist only of large dust particles.



5. Once formed, meteor streams hasten the further disintegration of comets.

82. The author states that the research described in the first paragraph was undertaken in order to

1. determine the age of an actual meteor stream



2. Identify the various structural features of meteor streams



3. explore the nature of a particularly interesting meteor stream



4. test the hypothesis that meteor streams become broader as they age



5. show that a computer model could help in explaining actual astronomical data

83. It can be inferred from the passage that which of the following would most probably be observed during the Earth’s passage through a meteor stream if the conventional theories mentioned in line 18 were true

1. Meteor activity would gradually increase to a single, intense peak, and then gradually decline.



2. Meteor activity would be steady throughout the period of the meteor shower.



3. Meteor activity would rise to a peak at the beginning and at the end of the meteor shower.



4. Random bursts of very high meteor activity would be interspersed with periods of very little activity.



5. In years in which the Earth passed through only the outer areas of a meteor stream, meteor activity would be absent.

84. According to the passage, why do the dust particles in a meteor stream eventually surround a comet’s original orbit?

1. They are ejected by the comet at differing velocities.



2. Their orbits are uncontrolled by planetary gravitational fields.



3. They become part of the meteor stream at different times.



4. Their velocity slows over time.



5. Their ejection velocity is slower than that of the comet.

85. The passage suggests that which of the following is a prediction concerning meteor streams that can be derived from both the conventional theories mentioned in line 18 and the new computer-derived theory?

1. Dust particles in a meteor stream will usually be distributed evenly throughout any cross section of the steam.



2. The orbits of most meteor streams should cross the orbit of the Earth at some point and give rise to a meteor shower.



3. Over time the distribution of dust in a meteor stream will usually become denser at the outside edges of the stream than at the center.



4. Meteor showers caused by older meteor streams should be, on average, longer in duration than those caused by very young meteor streams.



5. The individual dust particles in older meteor streams should be, on average, smaller than those that compose younger meteor streams.

86. It can be inferred from the last paragraph of the passage that which of the following must be true of the Earth as it orbits the Sun?

1. Most meteor streams it encounters are more than 2,000 years old.



2. When passing through a meteor stream, it usually passes near to the stream’s center.



3. It crosses the Geminid meteor stream once every year.



4. It usually takes over a day to cross the actual Geminid meteor stream.



5. It accounts of most of the gravitational perturbation affecting the Geminid meteor stream.

87. Which of the following is an assumption underlying the last sentence of the passage?

1. In each of the years between 1970 and 1979, the Earth took exactly 19 hours to cross the Geminid meteor stream.



2. The comet associated with the Geminid meteor stream has totally disintegrated.



3. The Geminid meteor stream should continue to exist for at least 5,000 years.



4. The Geminid meteor stream has not broadened as rapidly as the conventional theories would have predicted.



5. The computer-model Geminid meteor stream provides an accurate representation of the development of the actual Geminid stream.

我觉得OG里面的这篇比钻石更难些。

认认真真

JJ加油！！！