[Data Sufficiency]
试题详情
题目：
What is the value of x^2yz+xy^2z+xyz^2
(1) x+y+z=18
(2) xyz=10
选项:
答案:
C
问答
2答疑
2答疑
[Reading Comprehension]
试题详情
文章：
Companies that must determine well in advance of the selling season how many unites of a new product to manufacture often underproduce products that sell well and have overstocks of others. The increased incidence in recent years of mismatches between production and demand seems ironic, since point-of-sale scanners have improved data on consumers' buying patterns and since flexible manufacturing has enabled companies to produce, cost-effectively, small quantities of goods. This type of manufacturing has greatly increased the number of new products introduced annually in the United States. However, frequent introductions of new products have two problematic side effects. For one, they reduce the average lifetime of products; more of them are neither at the beginning of their life (when prediction is difficult) or at the end of their life (when keeping inventory is expensive because the products will soon become obsolete). For another, as new products proliferate, demand is divided among a growing number of stock-keeping units (SKU's). Even though manufacturers and retailers can forecast aggregate demand with some certainty, forecasting accurately how that demand will be distributed among the many SKU's they sell is difficult. For example, a company may be able to estimate accurately the aggregate number of shoes it will sell, but it may be uncertain about which specific types of shoes will sell more than other types.
题目：
The passage suggests which of the following about divided demand among a growing number of SKU's?
选项:
A、It has increased the average lifetime of products.
B、It has resulted from retailer's attempts to predict demand more accurately and avoid both understocks and overstocks.
C、It has decreased the use of flexible manufacturing by companies.
D、It has not increased the expense of keeping inventory of certain products.
E、It has not prevented companies from predicting aggregate demand with some certainty.
答案:
E
2答疑
[Problem Solving]
试题详情
题目：
The function f is defined for each positive three-digit integer n by f ( n ) = 2x 3y 5z, where x , y and z are the hundreds, tens, and units digits of n , respectively. If m and v are three-digit positive integers such that f ( m ) = 9 f ( v ), then m - v =
选项:
A、8
B、9
C、18
D、20
E、80
答案:
D
2答疑
[Reading Comprehension]
试题详情
文章：
Planter-legislators of the post-Civil War southern United States enacted crop lien laws stipulating that those who advanced cash or supplies necessary to plant a crop would receive, as security, a claim, or lien, on the crop produced. In doing so, planters, most of whom were former slaveholders, sought access to credit from merchants and control over nominally free laborers--former slaves freed by the victory of the northern Union over the southern Confederacy in the United States Civil War. They hoped to reassure merchants that despite the emancipation of the slaves, planters would produce crops and pay debts. Planters planned to use their supply credit to control their workers, former slaves who were without money to rent land or buy supplies. Planters imagined continuation of the pre-Civil War economic hierarchy: merchants supplying landlords, landlords supplying laborers, and laborers producing crops from which their scant wages and planters' profits would come, allowing planters to repay advances. Lien laws frequently had unintended consequences, however, thwarting the planter fantasy of mastery without slavery. The newly freed workers, seeking to become self-employed tenant farmers rather than wage laborers, made direct arrangements with merchants for supplies. Lien laws, the centerpiece of a system designed to create a dependent labor force, became the means for workers, with alternative means of supply advances, to escape that dependence.
题目：
According to the passage, each of the following was a reason planters supported crop lien laws EXCEPT:
选项:
A、Planters believed that lien laws would allow them to expand their landholdings.
B、Planters expected that lien laws would give them control over former slaves.
C、Planters anticipated that lien laws would help them retain access to merchant credit.
D、Planters intended to use lien laws to create a dependent labor force.
E、Planters saw lien laws as a way to maintain their traditional economic status.
答案:
A
2答疑
[Critical Reasoning]
试题详情
题目：
Columnist: People should avoid using a certain artificial fat that has been touted as a resource for those whose medical advisers have advised them to reduce their fat intake. Although the artificial fat, which can be used in place of fat in food preparation, has none of the negative health effects of fat, it does have a serious drawback: it absorbs certain essential vitamins, thereby preventing them from being used by the body.
In evaluating the columnist's position, it would be most useful to determine which of the following?
选项:
A、Whether increasing one's intake of the vitamins can compensate for the effects of the artificial fat
B、Whether the vitamins that the artificial fat absorbs are present in foods that contain the fat
C、Whether having an extremely low fat intake for an extended period can endanger the health
D、Whether there are any foods that cannot be prepared using the artificial fat as a substitute for other fats
E、Whether people are generally able to detect differences in taste between foods prepared using the artificial fat and foods that are similar except for the use of other fats
答案:
A
2答疑
[Data Sufficiency]
试题详情
题目：
If I and k are lines in the xy-plane, is the product of the slopes of l and k equal to -1 ?
(1) Line I passes through the origin and the point (1, 2).
(2) Line k has x-intercept 4 and y-intercept 2.
(1) Line I passes through the origin and the point (1, 2).
(2) Line k has x-intercept 4 and y-intercept 2.
选项:
A、Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B、Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C、BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D、EACH statement ALONE is sufficient.
E、Statements (1) and (2) TOGETHER are NOT sufficient.
答案:
C
2答疑
[Sentence Correction]
试题详情
题目：
The four-million-year-old fossilized skeleton known as Lucy is so small compared with many other skeletons presumed to be of the same species, and so some paleontologists have argued that Lucy represents a different lineage.
选项:
A、presumed to be of the same species, and so
B、presumed to be of the same species that
C、presumed that they are of the same species, and so
D、that they have presumed to be of the same species, so that
E、that they have presumed are of the same species, and
答案:
B
2答疑
[Reading Comprehension]
试题详情
文章：
Earth's surface consists of rigid plates that are constantly shifting and jostling one another. Plate movements are the surface expressions of motions in the mantle—the thick shell of rock that lies between Earth's crust and its metallic core. Although the hot rock of the mantle is a solid, under the tremendous pressure of the crust and overlying rock of the mantle, it flows like a viscous liquid. The mantle's motions, analogous to those in a pot of boiling water, cool the mantle by carrying hot material to the surface and returning cooler material to the depths. When the edge of one plate bends under another and its cooler material is consumed in the mantle, volcanic activity occurs as molten lava rises from the downgoing plate and erupts through the overlying one.
Most volcanoes occur at plate boundaries. However, certain "misplaced" volcanoes far from plate edges result from a second, independent mechanism that cools the deep interior of Earth. Because of its proximity to Earth's core, the rock at the base of the mantle is much hotter than rock in the upper mantle. The hotter the mantle rock is, the less it resists flowing. Reservoirs of this hot rock collect in the base of the mantle. When a reservoir is sufficiently large, a sphere of this hot rock forces its way up through the upper mantle to Earth's surface, creating a broad bulge in the topography. The "mantle plume" thus formed, once established, continues to channel hot material from the mantle base until the reservoir is emptied. The surface mark of an established plume is a hot spot—an isolated region of volcanoes and uplifted terrain located far from the edge of a surface plate. Because the source of a hot spot remains fixed while a surface plate moves over it, over a long period of time an active plume creates a chain of volcanoes or volcanic islands, a track marking the position of the plume relative to the moving plate. The natural history of the Hawaiian island chain clearly shows the movement of the Pacific plate over a fixed plume.
Most volcanoes occur at plate boundaries. However, certain "misplaced" volcanoes far from plate edges result from a second, independent mechanism that cools the deep interior of Earth. Because of its proximity to Earth's core, the rock at the base of the mantle is much hotter than rock in the upper mantle. The hotter the mantle rock is, the less it resists flowing. Reservoirs of this hot rock collect in the base of the mantle. When a reservoir is sufficiently large, a sphere of this hot rock forces its way up through the upper mantle to Earth's surface, creating a broad bulge in the topography. The "mantle plume" thus formed, once established, continues to channel hot material from the mantle base until the reservoir is emptied. The surface mark of an established plume is a hot spot—an isolated region of volcanoes and uplifted terrain located far from the edge of a surface plate. Because the source of a hot spot remains fixed while a surface plate moves over it, over a long period of time an active plume creates a chain of volcanoes or volcanic islands, a track marking the position of the plume relative to the moving plate. The natural history of the Hawaiian island chain clearly shows the movement of the Pacific plate over a fixed plume.
题目：
The author's reference to the Hawaiian Islands serves primarily to
选项:
A、provide an example of a type of volcanic activity that does not occur elsewhere
B、identify the evidence initially used to establish that the Pacific plate moves
C、call into question a theory about the source of the volcanoes that created the Hawaiian Islands
D、illustrate the distance from plate edges at which volcanoes typically appear
E、provide an example of how mantle plumes manifest themselves on Earth's surface
答案:
E
2答疑
[Sentence Correction]
试题详情
题目：
Biologists working in Spain say that their discovery of teeming life in a highly acidic river may not only broaden the search for life, or for evidence of past life, no other planets but also show that a number of forms of microscopic life can adapt to conditions that scientists have long thought hostile to all but the hardiest bacteria.
选项:
A、show that a number of forms of microscopic life can adapt to conditions that scientists have long thought hostile to all but the hardiest bacteria
B、may show that a number of forms of microscopic life is capable of adapting to conditions that scientists have long thought hostile to all bacteria but the hardiest ones
C、shows a number of forms of microscopic life to be capable to adapt to conditions that scientists have long thought had been hostile to all but the hardiest bacteria
D、showing that a number of forms of microscopic life is capable of adapting to conditions that scientists have long thought had been hostile to all but the hardiest bacteria
E、showing that a number of forms of microscopic life can adapt to conditions that scientists have long thought hostile to all bacteria but the hardiest
答案:
A
2答疑
[Reading Comprehension]
试题详情
文章：
题目：
Which of the following, if true, would most clearly support the contention attributed to SPEW in lines 17–20?
选项:
A、Those white lead factories that most strongly enforced regulations concerning worker safety and hygiene had the lowest incidences of lead poisoning among employees.
B、The incidence of lead poisoning was much higher among women who worked in white lead factories than among women who worked in other types of factories.
C、There were many household sources of lead that could have contributed to the incidence of lead poisoning among women who also worked outside the home in the late nineteenth century.
D、White lead factories were more stringent than were certain other types of factories in their enforcement of workplace safety regulations.
E、Even brief exposure to the conditions typically found in white lead factories could cause lead poisoning among factory workers.
答案:
A
0评分
447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
1499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
1687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
635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
1462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
1043浏览
0评分
692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
704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
166965浏览
0评分
174079浏览
