[Problem Solving]
试题详情
题目：
A coin that is tossed will land heads or tails, and each outcome has equal probability. What is the probability that the coin will land heads at least once on two tosses?
选项:
A、1/4
B、1/3
C、1/2
D、2/3
E、3/4
答案:
E
问答
2答疑
2答疑
[Reading Comprehension]
试题详情
文章：
| Line | There are recent reports of apparently drastic |
| declines in amphibian populations and of extinctions | |
| of a number of the world’s endangered amphibian | |
| species. These declines, if real, may be signs of a | |
| (5) | general trend toward extinction, and many |
| environmentalists have claimed that immediate | |
| environmental action is necessary to remedy | |
| this “amphibian crisis,” which, in their view, is an | |
| indicator of general and catastrophic environmental | |
| (10) | degradation due to human activity. |
| To evaluate these claims, it is useful to make a | |
| preliminary distinction that is far too often ignored. | |
| A declining population should not be confused with | |
| an endangered one. An endangered population is | |
| (15) | always rare, almost always small, and, by definition, |
| under constant threat of extinction even without a | |
| proximate cause in human activities. Its disappearance, | |
| however unfortunate, should come as no great | |
| surprise. Moreover, chance events—which may | |
| (20) | indicate nothing about the direction of trends in |
| population size—may lead to its extinction. The | |
| probability of extinction due to such random factors | |
| depends on the population size and is independent of | |
| the prevailing direction of change in that size. | |
| (25) | For biologists, population declines are potentially |
| more worrisome than extinctions. Persistent | |
| declines, especially in large populations, indicate a | |
| changed ecological context. Even here, distinctions | |
| must again be made among declines that are only | |
| (30) | apparent (in the sense that they are part of habitual |
| cycles or of normal fluctuations), declines that take | |
| a population to some lower but still acceptable | |
| level, and those that threaten extinction (e.g., by | |
| taking the number of individuals below the minimum | |
| (35) | viable population). Anecdotal reports of population |
| decreases cannot distinguish among these | |
| possibilities, and some amphibian populations have | |
| shown strong fluctuations in the past. | |
| It is indisputably true that there is simply not | |
| (40) | enough long-term scientific data on amphibian |
| populations to enable researchers to identify real | |
| declines in amphibian populations. Many fairly | |
| common amphibian species declared all but extinct | |
| after severe declines in the 1950s and 1960s | |
| (45) | have subsequently recovered, and so might |
| the apparently declining populations that have | |
| generated the current appearance of an amphibian | |
| crisis. Unfortunately, long-term data will not soon | |
| be forthcoming, and postponing environmental | |
| (50) | action while we wait for it may doom species and |
| whole ecosystems to extinction. |
题目：
It can be inferred from the passage that the author believes which of the following to be true of the environmentalists mentioned in lines 5–6 ?
选项:
A、They have wrongly chosen to focus on anecdotal reports rather than on the long-term data that are currently available concerning amphibians.
B、Their recommendations are flawed because their research focuses too narrowly on a single category of animal species.
C、Their certainty that population declines in general are caused by environmental degradation is not warranted.
D、They have drawn premature conclusions concerning a crisis in amphibian populations from recent reports of declines.
E、They have overestimated the effects of chance events on trends in amphibian populations.
答案:
D
2答疑
[Reading Comprehension]
试题详情
文章：
| Line | Ecoefficiency (measures to minimize environmental |
| impact through the reduction or elimination of waste | |
| from production processes) has become a goal for | |
| companies worldwide, with many realizing significant | |
| (5) | cost savings from such innovations. Peter Senge and |
| Goran Carstedt see this development as laudable | |
| but suggest that simply adopting ecoefficiency | |
| innovations could actually worsen environmental | |
| stresses in the future. Such innovations reduce | |
| (10) | production waste but do not alter the number of |
| products manufactured nor the waste generated | |
| from their use and discard; indeed, most companies | |
| invest in ecoefficiency improvements in order to | |
| increase profits and growth. Moreover, there is no | |
| (15) | guarantee that increased economic growth from |
| ecoefficiency will come in similarly ecoefficient | |
| ways, since in today’s global markets, greater profits | |
| may be turned into investment capital that could easily | |
| be reinvested in old-style eco-inefficient industries. | |
| (20) | Even a vastly more ecoefficient industrial system |
| could, were it to grow much larger, generate more | |
| total waste and destroy more habitat and species | |
| than would a smaller, less ecoefficient economy. | |
| Senge and Carstedt argue that to preserve the global | |
| (25) | environment and sustain economic growth, |
| businesses must develop a new systemic approach | |
| that reduces total material use and total accumulated | |
| waste. Focusing exclusively on ecoefficiency, which | |
| offers a compelling business case according to | |
| (30) | established thinking, may distract companies from |
| pursuing radically different products and business | |
| models. |
题目：
The passage implies that which of the following is a possible consequence of a company’s adoption of innovations that increase its ecoefficiency?
选项:
A、Company profits resulting from such innovations may be reinvested in that company with no guarantee that the company will continue to make further improvements in ecoefficiency.
B、Company growth fostered by cost savings from such innovations may allow that company to manufacture a greater number of products that will be used and discarded, thus worsening environmental stress.
C、A company that fails to realize significant cost savings from such innovations may have little incentive to continue to minimize the environmental impact of its production processes.
D、A company that comes to depend on such innovations to increase its profits and growth may be vulnerable in the global market to competition from old-style eco-inefficient industries.
E、A company that meets its ecoefficiency goals is unlikely to invest its increased profits in the development of new and innovative ecoefficiency measures.
答案:
B
2答疑
[Critical Reasoning]
试题详情
题目：
While many people think of genetic manipulation of food crops as being aimed at developing larger and larger plant varieties, some plant breeders have in fact concentrated on discovering or producing dwarf varieties, which are roughly half as tall as normal varieties.
Which of the following would, if true, most help to explain the strategy of the plant breeders referred to above?
Which of the following would, if true, most help to explain the strategy of the plant breeders referred to above?
选项:
A、Plant varieties used as food by some are used as ornamentals by others.
B、The wholesale prices of a given crop decrease as the supply of it increases.
C、Crops once produced exclusively for human consumption are often now used for animal feed.
D、Short plants are less vulnerable to strong wind and heavy rains.
E、Nations with large industrial sectors tend to consume more processed grains.
答案:
D
2答疑
[Data Sufficiency]
试题详情
题目：
In quadrilateral ABCD, is angle BCD a right angle?
(1) Angle ABC is a right angle.
(2) Angle ADC is a right angle.
选项:
答案:
E
2答疑
[Reading Comprehension]
试题详情
文章：
| Line | Conodonts, the spiky phosphatic remains (bones |
| and teeth composed of calcium phosphate) of | |
| tiny marine animals that probably appeared about | |
| 520 million years ago, were once among the most | |
| (5) | controversial of fossils. Both the nature of the |
| organism to which the remains belonged and the | |
| function of the remains were unknown. However, | |
| since the 1981 discovery of fossils preserving not | |
| just the phosphatic elements but also other remains | |
| (10) | of the tiny soft-bodied animals (also called conodonts) |
| that bore them, scientists' reconstructions of the | |
| animals' anatomy have had important implications | |
| for hypotheses concerning the development of the | |
| vertebrate skeleton. | |
| (15) | The vertebrate skeleton had traditionally been |
| regarded as a defensive development, champions of | |
| this view postulating that it was only with the much | |
| later evolution of jaws that vertebrates became | |
| predators. The first vertebrates, which were soft- | |
| (20) | bodied, would have been easy prey for numerous |
| invertebrate carnivores, especially if these early | |
| vertebrates were sedentary suspension feeders. | |
| Thus, traditionalists argued, these animals developed | |
| coverings of bony scales or plates, and teeth were | |
| (25) | secondary features, adapted from the protective |
| bony scales. Indeed, external skeletons of this | |
| type are common among the well-known fossils of | |
| ostracoderms, jawless vertebrates that existed from | |
| approximately 500 to 400 million years ago. | |
| (30) | However, other paleontologists argued that many of |
| the definitive characteristics of vertebrates, such as | |
| paired eyes and muscular and skeletal adaptations | |
| for active life, would not have evolved unless the | |
| (35) | first vertebrates were predatory. Teeth were more |
| primitive than external armor according to this view, | |
| and the earliest vertebrates were predators. | |
| The stiffening notochord along the back of the | |
| body, V-shaped muscle blocks along the sides, | |
| (40) | and posterior tail fins help to identify conodonts as |
| among the most primitive of vertebrates. The lack of | |
| any mineralized structures apart from the elements | |
| in the mouth indicates that conodonts were more | |
| primitive than the armored jawless fishes such as the | |
| (45) | ostracoderms. It now appears that the hard parts that |
| first evolved in the mouth of an animal improved its | |
| efficiency as a predator, and that aggression rather | |
| than protection was the driving force behind the origin | |
| of the vertebrate skeleton. |
题目：
According to the passage, the anatomical evidence provided by the preserved soft bodies of conodonts led scientists to conclude that
选项:
答案:
D
2答疑
[Critical Reasoning]
试题详情
文章：
Kitchen magazine plans to license the use of its name by a line of cookware. For a magazine, licensing the use of its name for products involves some danger, since if the products disappoint consumers, the magazine's reputation suffers, with consequent reductions in circulation and advertising. However, experts have evaluated the cookware and found it superior to all other cookware advertised in Kitchen. Therefore, Kitchen can collect its licensing fee without endangering its other revenues.
题目：
The argument above assumes which of the following?
选项:
A、No other line of cookware is superior to that which will carry the Kitchen name. Kitchen will not license the use of its name for any products other than the line of cookware.
B、Makers of cookware will not find Kitchen a less attractive advertising vehicle because the magazine's name is associated with a competing product.
C、Consumers who are not regular readers of Kitchen magazine will be attracted to the cookware by the Kitchen name.
D、Kitchen is one of the most prestigious cooking-related magazines.
答案:
C
2答疑
[Critical Reasoning]
试题详情
题目：
The Calex Telecommunications Company is planning to introduce cellular telephone service into isolated coastal areas of Caladia, a move which will require considerable investment. However, the only significant economic activity in these areas is small-scale coffee farming, and none of the coffee farmers make enough money to afford the monthly service fees that Calex would have to charge to make a profit. Nevertheless, Calex contends that making the service available to these farmers will be profitable.
Which of the following, if true, provides the strongest support for Calex's contention?
选项:
A、Currently, Caladian coffee farmers are forced to sell their coffee to local buyers at whatever price those buyers choose to pay because the farmers are unable to remain in contact with outside buyers who generally offer higher prices.
B、In the coastal areas of Caladia where Calex proposes to introduce cellular telephone service, there is currently no fixed-line telephone service because fixed-line companies do not believe that they could recoup their investment.
C、A cellular telephone company can break even with a considerably smaller number of subscribers than a fixed-line company can, even in areas such as the Caladian coast, where there is no difficult terrain to drive up the costs of installing fixed lines.
D、Calex bases its monthly fees for cellular telephone service in a given region partly on the cost of installing the necessary equipment to provide the service there.
E、Calex has for years made a profit on cellular telephone service in Caladia's capital city, which is not far from the coastal region.
答案:
A
2答疑
[Critical Reasoning]
试题详情
文章：
When species are extensively hunted, individuals that reach reproductive maturity early make up a larger proportion of the population, because they have a better chance of reproducing. When species face diminished food resources, on the other hand, individuals tend to take longer to reach reproductive maturity. These considerations may help settle whether the primary cause of the gradual disappearance of North America's mastodons, prehistoric animals related to elephants, was diminished food resources or human hunting, since __________.
题目：
Which of the following most logically completes the reasoning?
选项:
A、from the location of certain hunting weapons in juxtaposition with mastodon remains, it is possible to determine whether those weapons were used to hunt mastodonsthe average age at which mastodons reached reproductive maturity can be established from mastodon tusks, of which there are many fossils dating from different periods
B、from the remains of mastodons already discovered, it can be accurately estimated when mastodons became extinct
C、from tusks and other bones, it is possible to determine whether male and female mastodons reached reproductive maturity at about the same age
D、it is possible to determine whether the earliest human dwellings constructed from mastodon tusks and bones come from an earlier period than the earliest hunting weapons unambiguously associated with mastodon remains
答案:
B
2答疑
[Problem Solving]
试题详情
题目：
A certain quantity is measured on two different scales, the R-scale and the S-scale, that are related linearly. Measurements on the R-scale of 6 and 24 correspond to measurements on the S-scale of 30 and 60, respectively. What measurement on the R-scale corresponds to a measurement of 100 on the S-scale?
选项:
A、20
B、36
C、48
D、60
E、84
答案:
C
0评分
416浏览
[Undefined]
Art historian: Unlike many artistic traditions that sought to depict plants native to the local area in a seasonally appropriate way (for example, depicting scenes of spring with the plants in the appropriate stages of development for that season), seventeenth-century Dutch artists specializing in flower paintings almost exclusively chose to depict exotic species of flowers from outside the local area. Painting such species was worthwhile primarily because the art-buying public had developed a strong preference for images of the exotic. The great botanical centers of the time gave the artists direct access to such flowers, which the artists would freely combine in a single painting, regardless of whether the combined species occurred together in the wild, and depicted each in full bloom, regardless of whether those species bloomed at the same time in nature.
Statement: The art historian makes the point that the species of flowers these Dutch artists chose to paint were 1 largely because the species were 2 .
Select for 1 and for 2 the options that complete the statement so that it is most strongly supported by the information provided. Make only two selections, one in each column.
Statement: The art historian makes the point that the species of flowers these Dutch artists chose to paint were 1 largely because the species were 2 .
Select for 1 and for 2 the options that complete the statement so that it is most strongly supported by the information provided. Make only two selections, one in each column.
我选的CE，和EC有什么区别？怎么选出EC的？
0评分
1441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
1612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
618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
1423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
1005浏览
0评分
670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
689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
159797浏览
0评分
166906浏览
