问答

4答疑

[Reading Comprehension]

试题详情

文章:

    Diamonds are almost impossible to detect directly because they are so rare: very rich kimberlite pipes, the routes through which 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 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 diamond-stability field, where conditions of pressure and temperature are conducive to the formation of diamonds. If diamonds are to survive, though, they must shoot toward 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 in greater quantities than diamonds and eroded out of kimberlite pipes into the surrounding land. The standard ones are garnets, chromites, and ilmenites. One can spend years 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 are usually too sparse to mine.

    In the 1970's the process of locating profitable pipes was refined by focusing on the subtle differences between the chemical 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 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 formed only in the diamond-stability field; more commonly found versions came from elsewhere in the mantle. Gurney also found that though ilmenites did not form in the 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 reasoned that iron took on more or less oxygen in response to conditions in the kimberlitic magma itself—mainly in response to heat and the available oxygen. When iron became highly oxidized, so did diamonds; that is, they vaporized into carbon dioxide.

题目:

The primary purpose of the passage is to

选项:

A、discuss an objection to Gurney's theories about the uses of indicator minerals
B、explore the formation of diamonds and the reasons for their scarcity
C、analyze the importance of kimberlite pipes in the formation of diamonds
D、define the characteristics of indicator minerals under differing conditions
E、explain a method of determining whether kimberlite pipes are likely to contain diamonds

答案:

E
4答疑

[Sentence Correction]

试题详情

题目:

The new image of Stone Age people as systematic hunters of large animals, rather than merely scavenging for meat, have emerged from the examination of tools found in Germany, including three wooden spears that archaeologists believe to be about 400,000 years old.

选项:

A、merely scavenging for meat, have emerged from the examination of tools found in Germany, including
B、as merely scavenging for meat, have emerged from examining tools found in Germany, which include
C、as mere meat scavengers, has emerged from examining tools found in Germany that includes
D、mere scavengers of meat, has emerged from the examination of tools found in Germany, which includes
E、mere scavengers of meat, has emerged from the examination of tools found in Germany, including

答案:

E
4答疑

[Critical Reasoning]

试题详情

题目:

The violent crime rate (number of violent crimes per 1,000 residents) in Meadowbrook is 60 percent higher now than it was four years ago.  The corresponding increase for Parkdale is only 10 percent.  These figures support the conclusion that residents of Meadowbrook are more likely to become victims of violent crime than are residents of Parkdale.
 
The argument above is flawed because it fails to take into account

选项:

A、changes in the population density of both Parkdale and Meadowbrook over the past four years
B、how the rate of population growth in Meadowbrook over the past four years compares to the corresponding rate for Parkdale
C、the ratio of violent to nonviolent crimes committed during the past four years in Meadowbrook and Parkdale
D、the violent crime rates in Meadowbrook and Parkdale four years ago
E、how Meadowbrook's expenditures for crime prevention over the past four years compare to Parkdale's expenditures

答案:

D
4答疑

[Critical Reasoning]

试题详情

题目:

The total market value of real estate in Altonville has steadily declined over the past four years.  This decline has meant that the overall figure on which the city's property tax is based—the assessed value of that real estate—has also declined.  The percentage of assessed value that was paid as property taxes to the city, however, did not change from year to year during this period.
 
The information above most strongly supports which of the following?

选项:

A、The percentage of Altonville's yearly revenue that comes from money collected in property taxes did not change over the past four years.
B、The percentage of Altonville's yearly revenue that comes from money collected in property taxes has declined steadily over the past four years.
C、The amount of revenue that Altonville collected from property taxes was lower last year than it was four years ago.
D、During the past four years, Altonville officials increased tax rates on other sources of revenue such as retail sales and business profits.
E、Altonville will soon require property owners to pay a higher percentage of the assessed value of their property as property tax.

答案:

C
4答疑

[Reading Comprehension]

试题详情

文章:

    Firms traditionally claim that they downsize (i.e., make permanent personnel cuts) for economic reasons, laying off supposedly unnecessary staff in an attempt to become more efficient and competitive. Organization theory would explain this reasoning as an example of the "economic rationality" that it assumes underlies all organizational activities. There is evidence that firms believe they are behaving rationally whenever they downsize; yet recent research has shown that the actual economic effects of downsizing are often negative for firms. Thus, organization theory cannot adequately explain downsizing; non-economic factors must also be considered.

    One such factor is the evolution of downsizing into a powerful business myth: managers simply believe that downsizing is efficacious. Moreover, downsizing nowadays is greeted favorably by the business press; the press often refers to soaring stock prices of downsizing firms (even though research shows that stocks usually rise only briefly after downsizing and then suffer a prolonged decline).

    Once viewed as a sign of desperation, downsizing is now viewed as a signal that firms are serious about competing in the global marketplace; such signals are received positively by key actors-financial analysts, consultants, shareholders who supply firms with vital organizing resources. Thus, even if downsizers do not become economically more efficient, downsizing's mythic properties give them added prestige in the business community, enhancing their survival prospects.

题目:

The primary purpose of the passage is to

选项:

A、criticize firms for engaging in the practice of downsizing
B、analyze the negative economic impact of downsizing on firms
C、offer an alternative to a traditional explanation for the occurrence of downsizing
D、chronicle how perceptions of downsizing have changed over time
E、provide evidence disputing the prevalence of downsizing

答案:

C
4答疑

[Critical Reasoning]

试题详情

题目:

In virtually any industry, technological improvements increase labor productivity, which is the output of goods and services per person-hour worked. In Parland’s industries, labor productivity is significantly higher than it is in Vergia’s industries. Clearly, therefore, Parland’s industries must, on the whole, be further advanced technologically than Vergia’s are.

The argument is most vulnerable to which of the following criticisms?

选项:

A、It offers a conclusion that is no more than a paraphrase of one of the pieces of information provided in its support.
B、It presents as evidence in support of a claim information that is inconsistent with other evidence presented in support of the same claim.
C、It takes one possible cause of a condition to be the actual cause of that condition without considering any other possible causes.
D、It takes a condition to be the effect of something that happened only after the condition already existed.
E、It makes a distinction that presupposes the truth of the conclusion that is to be established.

答案:

C
4答疑

[Critical Reasoning]

试题详情

题目:

In a study conducted in Pennsylvania, servers in various restaurants wrote "Thank you" on randomly selected bills before presenting the bills to their customers.  Tips on these bills were an average of three percentage points higher than tips on bills without the message.  Therefore, if servers in Pennsylvania regularly wrote "Thank you" on restaurant bills, their average income from tips would be significantly higher than it otherwise would have been.
 
Which of the following is an assumption on which the argument relies?

选项:

A、The 'Thank you' messages would have the same impact on regular patrons of a restaurant as they would on occasional patrons of the same restaurant.
B、Regularly seeing 'Thank you' written on their bills would not lead restaurant patrons to revert to their earlier tipping habits.
C、The written 'Thank you' reminds restaurant patrons that tips constitute a significant part of the income of many food servers.
D、The rate at which people tip food servers in Pennsylvania does not vary with how expensive a restaurant is.
E、Virtually all patrons of the Pennsylvania restaurants in the study who were given a bill with 'Thank you' written on it left a larger tip than they otherwise would have.

答案:

B
4答疑

[Sentence Correction]

试题详情

题目:

At the annual stockholders meeting, investors heard a presentation on the numerous challenges facing the company, including among them the threat from a rival's multibillion-dollar patent-infringement suit and the declining sales for the company's powerful microprocessor chip.

选项:

A、including among them the threat from a rival's multibillion-dollar patent-infringement suit and the declining sales for
B、which includes the threat of a rival's multibillion-dollar patent-infringement suit and declining sales of
C、included among these the threat from a rival's multibillion-dollar patent-infringement suit as well as a decline in sales for
D、among them the threat of a rival's multibillion-dollar patent-infringement suit and the decline in sales of
E、among these the threat from a rival's multibillion-dollar patent-infringement suit as well as the decline in sales for

答案:

D
4答疑

[Critical Reasoning]

试题详情

题目:

Which of the following most logically completes the argument?

Sviatovin is a medieval Moringian text whose author and exact date of composition are unknown. However, the events in the life of Prince Sviatov that the text describes occurred in 1165, and in the diagram of Sviatov’s family that accompanies the text his father, who died in 1167, is identified as still living. Thus Sviatovin must have been written between 1165 and 1167, assuming that __________.

选项:

A、the life of Prince Sviatov is not the subject of any other medieval Moringian texts
B、the author of Sviatovin intended it to provide as accurate a report about Prince Sviatov’s exploits as possible
C、the diagram accurately represents the composition of Sviatov’s family at the time Sviatovin was written
D、Sviatovin is the earliest Moringian text whose composition can be dated to within a few years
E、Sviatovin was not written by Sviatov’s father himself

答案:

C
4答疑

[Critical Reasoning]

试题详情

题目:

Editorial: The roof of Northtown’s municipal equipment-storage building collapsed under the weight of last week’s heavy snowfall. The building was constructed recently and met local building-safety codes in every particular, except that the nails used for attaching roof supports to the building’s columns were of a smaller size than the codes specify for this purpose. Clearly, this collapse exemplifies how even a single, apparently insignificant departure from safety standards can have severe consequences.

Which of the following, if true, most seriously weakens the editorial’s argument?

选项:

A、The only other buildings to suffer roof collapses from the weight of the snowfall were older buildings constructed according to less exacting standards than those in the codes.
B、The amount of snow that accumulated on the roof of the equipment-storage building was greater than the predicted maximum that was used in drawing up the safety codes.
C、Because the equipment-storage building was not intended for human occupation, some safety-code provisions that would have applied to an office building did not apply to it.
D、The municipality of Northtown itself has the responsibility for ensuring that buildings constructed within its boundaries meet the provisions of the building-safety codes.
E、Because the equipment-storage building was used for storing snow-removal equipment, the building was almost completely empty when the roof collapsed.

答案:

B
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409浏览

[Undefined]

An unusually severe winter occurred in Europe after the continent was blanketed by a blue haze resulting from the eruption of the Laki Volcano in the European republic of Iceland in the summer of 1984.  Thus, it is evident that major eruptions cause the atmosphere to become cooler than it would be otherwise.
Which of the following statements, if true, most seriously weakens the argument above?
C选项为什么就不会有张冠李戴的问题呢,1984和1982的气候情况能一样吗,C里的火山就可以试用于原文的火山吗
0评分
470浏览

[Undefined]

The rate of a certain chemical reaction is directly proportional to the square of the concentration of chemical A present and inversely proportional to the concentration of chemical B present. If the concentration of chemical B is increased by 100 percent, which of the following is closest to the percent change in the concentration of chemical A required to keep the reaction rate unchanged?
为什么这个题一定是相乘不能是相加呢?y=k1A方-k2B (k1,k2大于0 ),也满足题目说的与A方成正比与B成反比啊?但是这道题只有相乘的情况才能选出正确答案
0评分
326浏览

[Undefined]

Tiger beetles are such fast runners that they can capture virtually any nonflying insect.  However, when running toward an insect, the beetles intermittently stop, and then, a moment later, resume their attack.  Perhaps they cannot maintain their pace and must pause for a moment's rest; but an alternative hypothesis is that while running tiger beetles are unable to process the resulting rapidly changing visual information, and so quickly go blind and stop.
 
Which of the following, if discovered in experiments using artificially moved prey insects, would support one of the two hypotheses and undermine the other?
答案C是怎么支持一个猜想又削弱另一个猜想的?
0评分
711浏览

[GWD]

The author of the passage implies that which of the following is a possible partial explanation for acquisition behavior during the 1970's and 1980's?
请解释这道题为什么不选C或E,除了正确选项B,我认为文中也正确地提到了这两个选项可以解释acquisition behavior during 1970s and 80s
0评分
618浏览

[OG]

The primary purpose of the passage is to
为什么选E不选B
0评分
408浏览

[Undefined]

Club X has more than 10 but fewer than 40 members. Sometimes the members sit at tables with 3 members at one table and 4 members at each of the other tables, and sometimes they sit at tables with 3 members at one table and 5 members at each of the other tables. If they sit at tables with 6 members at each table except one and fewer than 6 members at that one table, how many members will be at the table that has fewer than 6 members?
提问小梅老师 这道题求讲一下 我没什么思路 带入数字得的是3
0评分
416浏览

[Undefined]

A photography dealer ordered 60 Model X cameras to be sold for $250 each, which represents a 20 percent markup over the dealer's initial cost for each camera. Of the cameras ordered, 6 were never sold and were returned to the manufacturer for a refund of 50 percent of the dealer's initial cost. What was the dealer's approximate profit or loss as a percent of the dealer's initial cost for the 60 cameras?
请问小梅老师 这道题讲讲一下 我算的是19% 原来成本是200每个 亏了6个 每个亏100. 最后得不出答案
0评分
92043浏览

[Undefined]

Analytical!
请问may老师,这题该用什么思路来做?
0评分
99125浏览

[Undefined]

Analytical!
请问张老师,这道题为什么D不对?我有我觉得second paragraph最后一句话特别指向D
1评分
101086浏览

[Undefined]

Analytical!
请问老师,这道题为什么second part是”evidence”? 还有、不确定First part到底是background info还是premise?
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