备考记录—持续更新

Doris707

毫无章法的花了几个月的时间捡起英语，又毫无章法的花了一个多月来看GMAT，现在基本算是入门了，但是无奈做错的题很多，自己的基础太薄弱，想一步一个脚印地往下走。
今天花了很多时间做OG SC，看错题，看BeattheGMAT论坛，看到了几个Ron的回帖，思路非常清晰，很适合我作为学习材料，于是决定经常上去看看Ron回答的问题。

看完了M SC和FOV，做SC的时候，做错了就会想要自己分析，看看到底哪里对哪里错，哪里没掌握。今天决定改变这种策略，改变成做完SC就立刻看OG的解释，上论坛看讨论帖，查缺补漏。

721. Along the major rivers that traversethe deserts of northeast Africa, the Middle East, and northwest India, thecombination of a reliable supply of water and good growing conditions bothencouraged farming traditions that, in places, endure in at least 6,000years.

A. good growing conditions bothencouraged farming traditions that, in places, endure in

B. good growing conditions encouraged farming traditions that have, in places, endured for

C. of good growing conditions haveencouraged farming traditions that, in places, endured for

D. of good growing conditions bothencouraged farming traditions that have, in places, endured

E. of good growing conditions encouragedfarming traditions that have, in places, been enduring for

围绕该题的几个点：
1、关于E选项的现在完成进行时
have been + VERBing serves to express a CONTINUOUS ACTION.
Here, to endure means TO LAST.
To last is an action that -- on its own -- is continuous.
Since to endure on its own conveys a continuous action, theuse of a continous tense seems redundant.
http://www.beatthegmat.com/good-farming-og13-71-t116366.html
也就是说endure和现在完成进行时要传达的动作一直在进行，是重复的，所以redundant，所以OG说用力过猛

2、have been doing和have done
have been doing: CONTINUOUS Action，动作还在继续发生
have done: continuous Effect，动作已经结束，但是影响一直在持续
3、the combination 和 both的连用
wordy其实就是有重复含义的词重复出现，已经表明是结合water和growing condition，再说both显得多余
又如although和yet同时出现，也是wordy
4、and并列的到底是什么
the combinaton of A and B是表达A和B的结合
the combination of a reliable supply of A and of B这个of到底是在repeat哪一个of，不得而知，但是两个都不对
“It seems to indicate that there is both a combination of a reliable supply of water and a combination of good growing conditions.”——OG


从其他题中学到的：

过去进行时和过去时的区别：by Ron

"were VERBing" implies that theprocess was going on at the time, but that it didn't necessarily finish. in this context,that is at best questionable.
i.e.,
tom's mother was cutting hishair before the guests arrived --> thismakes it sound as though tom's mother didn't finish cutting his hair.
tom's mother cut his hairbefore the guests arrived --> shefinished the job.

Doris707

https://www.thoughtco.com/revising-sentences-with-absolute-phrases-1689690
这是从CD前辈的帖子里找到的，讲absolute phrases

Absolute phrases are useful constructions for adding details to an entire sentence—details that often describe one aspect of someone or something mentioned elsewhere in the sentence.

Doris707

What is to qualify?

To qualify is to add limitations or conditions. In RC, if a claim is presented, the author of the passage (or another expert within the passage) can qualify the claim by showing that something else should be taken into consideration, or that the claim has some limitation. https://www.beatthegmat.com/what-is-meant-by-qualify-a-claim-t62417.html#278023

Doris707

CD的前辈这样总结CR：

CR好像RC,用小安阅读法也可以哈哈哈。

为什么文中出现这句话，这句话有什么作用，和前后文又有什么关系。

做完后分析，为什么答案是这个，答案怎么在问文中体现。文中有什么提示词。  嘿嘿。
-- by 会员 yiayia (2012/2/19 20:08:59)

Doris707

CD的前辈babybearmm贴出来的一道CR题，看完之后我感受到了到底什么叫做assumption

Historically speaking, successful long-term investors have preferred mixed investment portfolios with lower overall risk to less diversified portfolios containing more high-risk investments. But recent research shows that the most profitable investors carry a higher percentage of risk in their portfolios. This illustrates that choosing to develop a higher-risk investment portfolio is a better investment decision than is choosing to maintain a mixed portfolio with lower risk.
Question
The conclusion drawn to the left relies upon which of the following assumptions?

The arguer here concludes that it is a better investment decision to choose a higher-risk portfolio with less diversity than it is to choose a lower-risk portfolio with more diversity. S/he does so by pointing to research that shows the most profitable investors make this decision. The assumption? That the most profitable investors must necessarily make better investment decisions than do those less profitable.


Choices
A
Mixed portfolios with lower risk do not provide significant return on investment.
This is consistent with the argument, but not a necessary missing piece of evidence. The word "significant" is also not easily defined and is too subjective.
B
Investors may either develop more diversified lower-risk portfolios or less diversified higher-risk portfolios.
Investment approaches available to investors is not the issue here. Rather, the question is one of better investment decision-making.
C
The returns on investment achieved by the most profitable investors can be achieved just as readily by less profitable investors.

Your answer was incorrect
The relative ease of investment decision-making among groups is not the issue here; rather, the issue is one of the quality of those decisions. While it may be the correct decision for everyone to invest in riskier portfolios, the returns are not necessarily achieved "just as readily" among different groups of people.
D
The most profitable investors invest the majority of the portfolios in higher-risk positions.
Proportions of overall investments are not important here;quality is.
E
The most profitable investors make better investment decisions than do those who receive a more modest return on investment.
This is the credited response. The author equates "high profitability" and "better investment decision" based on an assumption.
For the assumption question, we need to pay attention to terms appear in the conclusion that are not present in the premises. Here it is "make better investment decisions".  The author assumes that the most profitable investors make earnings based on clever invest management, i.e. based on good investment decision, rather than by chance or something.
通常来看，成功的长期投资者倾向于多样化的投资组合，整体性风险较小。
但是，最近的研究表明获得高利润的投资者，他们的投资组合是高风险的。
这表明选择建立一个高风险的投资组合，是一个更好的投资选择，相比保持一个混合的低风险投资组合来说。
是获得高利润的人自己选择的投资组合。

Doris707

平行结构中，不定式的to省略问题：

OG的解释：To preserve parallelism, the infinitive marker TO should appear ONLY before the first verb in the series OR it should appear before all three verbs
CD前辈整理的OG：
OG12 11
There are several ways to build solid walls using just mud or clay, but the most extensively used method has been to form the mud or clay into bricks, and, after some preliminary air drying or sun drying, to lay them  in the wall in mud mortar.
OG12 15
Warning that computers in the United States are not secure, the National Academy of Sciences has urged the nationto revamp computer security procedures, institute new emergency response teams, and create a special nongovernment organization to take  charge of
computer security planning.
OG12 51
A new study suggests that the conversational pace of everyday life may be so brisk that it hampers the ability of some children to distinguish discrete sounds and words and, as a result, to make  sense of speech.
OG12 55
Many house builders offer rent-to-buy programs that enable a family with insufficient savings for a conventional down payment to move into new housing and to apply  part of the rent to a purchase later.
OG12 62
When Congress reconvenes, some newly elected members from rural states will try to establish tighter restrictions on the amount of
grain farmers will be allowed to grow and to encourage  more aggressive sales of United States farm products overseas.

Doris707

only if条件句：

OG2017

706. The Organization of Petroleum Exporting Countries (OPEC) had long been expected to announce a reduction in output tobolster sagging oil prices, but officials of the organization just recently announced that the group will pare daily production by 1.5 million barrels by the beginning of next year,but only if non-OPEC nations, including Norway, Mexico, and Russia, were to trim output by a total of500,000 barrels a day.

A. year, but only if non-OPEC nations,including Norway, Mexico, and Russia, were to trim output

B. year, but only if the output of non-OPECnations, which includes Norway, Mexico, and Russia, is trimmed

C. year only if the output of non-OPECnations, including Norway, Mexico, and Russia, would be trimmed

D. year only if non-OPEC nations, which includesNorway, Mexico, and Russia, were trimming output

E. year only if non-OPEC nations, including Norway, Mexico, andRussia, trim output

我自己不明白的是，if条件句用虚拟语气是可以的，但是为什么不选C。查了论坛之后，发现排除C的原因有三个：

1、including修饰有问题，像是跳跃修饰了the output，表达这些non-OPEC nations的output总和，原句是表达每个国家output削减

2、X will do something only if Y does something else. 是条件状语从句，主将从现，而不是虚拟语气

3、 if the output...would be trimmed

On the GMAT, if + SUBJECT + would is ALWAYS WRONG.


其他题目：
While some academicians believe that business ethics should be integrated into every business course, others say that students will take ethics seriously only if it would be taught as a separately required course.
(A) only if it would be taught as a separately required course
(B) only if it is taught as a separate, required course
(C) if it is taught only as a course required separately
(D) if it was taught only as a separate and required course
(E) if it would only be taught as a required course, separately

Choice B is best: in sentences expressing a conditional result (x will happen if y happens), the verb of the main clause should be in the future tense and the verb of the if clause should be in the present indicative. Thus, is taught (in B) is consistent with will take, whereas would be taught (in A and E) and was taught (in D) are not. For clarity, only in C, D, and E should immediately precede the entire if clause that it is meant to modify. Also, the intended meaning is distorted when the adverb separately is used to modify required, as in A and C, or taught, as in E; B correctly uses the adjective separate to modify course.

GWD

Antarctica receives more solar radiation than does any other place on Earth, yet the temperatures are so cold and the ice cap is reflective, so that little polar ice melts during the summer; otherwise, the water levels of the oceans would rise 250 feet and engulf most of the world’s great cities.
A.is reflective, so that little polar ice melts during the summer; otherwise,
B.is so reflective that little of the polar ice melts during the summer; were it to do so,
C.so reflective that little polar ice melts during the summer, or else
D.reflective, so that little of the polar ice melts during the summer, or
E.reflects so that little of the polar ice melts during the summer; if it did
答案选B. were it to do so...表示条件, = if it were to do so. 符合规律的。



曼哈顿：
虚拟语气
Subjunctive Mood in two special situations:
(1) Unlikely or unreal conditions (usually after if on a similar word). —— the Hypothetical Subjunctive
(2) Proposals, desires, and requests formed with certain verbs and the word that. ——the Command Subjunctive
These two uses correspond to two forms of the subjunctive mood: the Hypothetical Subjunctive and the Command Subjunctive.



We use the Hypothetical Subjunctive form in a few circumstances to indicate unlikely or unreal conditions. Principally, this form occurs after if、 as if、 or as though.
Right: To overcome my fear of germs, I will think about disease as though it WERE harmless.
The speaker does not believe that disease actually is harmless. By using the Hypothetical Subjunctive were, the speaker reveals that he or she thinks that disease is not harmless.
The basic form of the Hypothetical Subjunctive is equivalent to the Simple Past of every verb, with one exception. For the verb to be, the form were is always used. (The Simple Past of be is both were and was: I was, you were, he/she/it was, we/you/they were) Just remember the song “If I WERE a Rich Man” (not If I WAS a Rich Man) and you will remember to use were. However, the GMAT tests this usage only rarely. Because of its similarity in form to the Simple Past, the Hypothetical Subjunctive is sometimes called the “Past Subjunctive.” However, its use has to do with unlikely or unreal conditions, not with past time.
通过错的去表达对的，去强调这个不是真实的，很多时候是表达一种主观的判断，只要自己认为与真实的不一样就行


If... Then Constructions根据发生与否的确定性来划分：
Right:
IF you study diligently, [THEN] you will score highly.
You will score highly IF you study diligently.

五种形式都是对的，根据句意来看：
(1) General Rule with no uncertainty 非常确定会发生
IF Sophie EATS pizza, THEN she BECOMES ill. IF Present, THEN Present.
This pattern is equivalent to whenever: WHENEVER Sophie EATS pizza, she BECOMES ill,
(2) General Rule with some uncertainty 有一点不确定性
IF Sophie EATS pizza, THEN she MAY BECOME ill. IF Present, THEN Can or May.
Here, the helping verbs can or may can be used to allow for a somewhat uncertain outcome.
(3) Particular Case (in the future) with no uncertainty  确定将会发生
IF Sophie EATS pizza tomorrow, THEN she WILL BECOME ill. IF Present, THEN Future.
Another possibility for the Particular Case (in the present) is Present Perfect: If Sophie HAS EATEN pizza, then she WILL BECOME ill.
(4) Unlikely Case (in the future)  不可能发生
IF Sophie ATE pizza tomorrow, THEN she WOULD BECOME ill. IF Hypothetical Subjunctive, THEN Conditional.
Here, the writer thinks that Sophie is unlikely to eat pizza tomorrow. The Conditional Tense (would) shows the hypothetical result of an unlikely or untrue condition. In place of would, the form could can be used to indicate improbability as well.
(5) Case That Never Happened (in the past)  
IF Sophie HAD EATEN pizza yesterday, THEN she WOULD HAVE BECOME ill. IF Past Perfect, THEN Conditional Perfect.
Other patterns are possible, but if... then sentences that you encounter on the GMAT should conform to one of these five patterns.
The helping verbs would and should should NEVER go in the if part of the sentence, according to the GMAT! 也就是本题中： if the output...would be trimmed 是错的

The Organization of Petroleum Exporting Countries (OPEC) had long been expected to announce a reduction in output tobolster sagging oil prices, but officials of the organization just recently announced that the group will pare daily production by 1.5 million barrels by the beginning of next year only if non-OPEC nations, including Norway, Mexico, andRussia, trim output by a total of 500,000 barrels a day.
一个句子中用了四个时态

Doris707

看论坛里，CD前辈是这么考虑一个SC问题的：
The development of a new jumbo rocket that is expected to carry the United States into its next phase of space exploration will be able to deliver a heavier load of instruments into orbit than the space shuttle and at a lower cost.
(A) The development of a new jumbo rocket that is expected to carry the United States into its next phase of space exploration will be able to deliver a heavier load of instruments into orbit than the space shuttle and at a lower cost.
(B) The development of a new jumbo rocket is expected to carry the United States into its next phase of space exploration and be able to deliver a heavier load of instruments into orbit at a lower cost than the space shuttle.
(C) The new development of a jumbo rocket, which is expected to carry the United States into its next phase of space exploration, will be able to deliver a heavier load of instruments into orbit at a lower cost than the space shuttle.
(D) A newly developed jumbo rocket, which is expected to carry the United States into its next phase of space exploration, will be able to deliver a heavier load of instruments into orbit than the space shuttle can, and at a lower cost.
(E) A newly developed jumbo rocket, which is expected to carry the United States into its next phase of space exploration, will be able to deliver a heavier load of instruments into orbit than the space shuttle and to cost less.

我这么看这道题的，找主干意思，先找动词。这句话两点意思：
1. sth. is expected to carry the US into its next phase
2. sth. will be able to deliver X into orbit
注意两个动词：carry和deliver，以及各自在句子中的意思
然后这个sth.，到底是the development of the rocket呢，还是rocket呢？
第一点意思，从逻辑上，sth.可以是development，也可以是rocket，都说得通。
但是第二点意思，这里的sth.就必须是rocket才符合逻辑。

有了以上分析，然后考虑到以上第2点意思是句子的核心意思，第1点意思是补充信息，我们就知道，句子必然是这么写：
rocket, _______________, will be able to deliver X into orbit.
于是，纵向扫视选项开头，直接锁定D和E。至于D和E之间的split，相信你也明白。

思路应该是：
找到动词，找到主干——看动作发出这是谁，符不符合逻辑——句子的核心意思是什么（作者主要想说什么）——补充信息是什么——句子各成分应该怎么排布

Doris707

看了youtube上的CR视频，也是CD前辈babybearmm贴出来的，讲的清晰明了。
从这个视频中我发现了自己理解Assumption的误区，我以前理解Assumption就是读完文段之后开始头脑风暴，自己“构造”出一个Assumption，脱离了文段，但是应该紧扣文段，直接从文段中找到gap。
GMAT Prep - Verbal - Critical Reasoning - Weakening Arguments by Knewton  http://www.youtube.com/watch?v=EJGw9DAfSCE&feature=player_embedded#!

视频中提到：
An argument consist of evidence、stated facts，and assumptions，unstated but necessary premises，that lead to a conclusion. 通常情况下，weaken一个argument就是attack这些assumptions，因为asp is uncertain and usually is false而evidence是事实，不能dispute
e.g.Burt is tall 统计显示，同样岗位和同样的job qualification，高的人工资也比矮的人高。Jeff比较矮，并且他有着和Burt一样的years of experiences。因此，如果B和J在同样的岗位上，B的工资会比J的高。
evidence: 统计显示，同样岗位和同样的job qualification，高的人工资也比矮的人高
premise: Jeff比较矮，并且他有着和Burt一样的years of experiences
concluion: 同样的岗位上, B的工资会比J的高
assumption：job qualification和years of experiences是一回事
所以，要weaken，就要从攻击assumption入手，指出asp的存在
The number of years of experiences that an applicant has is one of many significants job qualification.  CORRECT
Burt might be hired for a less well-paying position than Jeff, so Burt might earn less than Jeff despite his height.  INCORRECT
文中已经说明，他们是same position，反驳stated fact不能削弱argument

Doris707

Weaken: denying an assumption  指出aspAsp = link between evidence and conclusion
e.g. Consuming a half-cup of healthy nuts per day has been shown to improve the speed at which certain mental tasks can be performed.  Therefore, consuming a half-cup of peanuts per day would improve graduate students' performance on exam.
Asp 1: healthy nuts = peanuts → deny: peanuts are a kind of healthy nuts →"peanuts are not considered heathy nuts"
Asp 2: improve mental task speed可以improve students' perfomance on exam(the mental tasks helped by nuts will impact graduate students' exam peoformance→ deny: "the mental tasks whose speed can be increased by eating healthy nuts are not performed while a student is taking an exam.)

我一开始看第二个Asp的时候，认为是mental task = performance on exam，离真正有用的Asp差了一步，真正有用的Asp是读出了隐含意思。

Weaken: denying an asp using additional evidence  说出asp不对
Asp 1 : healthy nuts = peanuts → deny: healthy nuts are less than 30% fat; peanuts are 50% fat.
Asp 2： the mental tasks whose speed can be increased by eating healthy nuts are performed on X, X is different with exam.  


Strenghten: affirming an asp
Asp 1: healthy nuts = peanuts → affiming: healthy nuts are less than 60% fat; peanuts are 50% fat

所以，我的下一步就是找准文段中的Asp