[Problem Solving]
试题详情
题目：
If x is a negative integer, which of the following expressions has the LEAST value?
选项:
A、x2 - 0.50
B、x2 - 0.51
C、x3 - 0.502
D、x3 - 0.511
E、x3 - 0.512
答案:
D
问答
2答疑
2答疑
[Sentence Correction]
试题详情
题目：
The airline company, following through on recent warnings that it might start reducing service, announced that it was eliminating jet service to nine cities, closing some unneeded operations, and it grounded twenty-two planes.
选项:
A、 closing some unneeded operations, and it grounded
B、 closing some unneeded operations, and grounding
C、 was closing some unneeded operations, while it grounded
D、 it closed some unneeded operations and grounded
E、 it was closing some unneeded operations, and grounding
答案:
B
2答疑
[Sentence Correction]
试题详情
题目：
The Industrial Revolution, making it possible to mass-produce
manufactured goods, was marked by their use of new machines,
new energy sources, and new basic materials.
选项:
A、making it possible to mass-produce manufactured goods, was marked by their use of
B、making possible the mass production of manufactured goods, marked by the use of
C、which made it possible that manufactured goods were mass-produced, was marked by their using
D、which made possible the mass production of manufac-tured goods, was marked by the use of
E、which made the mass production of manufactured goods possible and was marked by using.
答案:
D
2答疑
[Critical Reasoning]
试题详情
题目：
State spokesperson: Many businesspeople who have not been to our state believe that we have an inadequate road system. Those people are mistaken, as is obvious from the fact that in each of the past six years, our state has spent more money per mile on road improvements than any other state.
Which of the following, if true, most seriously undermines the reasoning in the spokesperson's argument?
选项:
A、In the spokesperson's state, spending on road improvements has been increasing more slowly over the past six years than it has in several other states.
B、Adequacy of a state's road system is generally less important to a businessperson considering doing business there than is the availability of qualified employees.
C、Over the past six years, numerous businesses have left the spokesperson's state, but about as many businesses have moved into the state.
D、In general, the number of miles of road in a state's road system depends on both the area and the population of the state.
E、Only states with seriously inadequate road systems need to spend large amounts of money on road improvements.
答案:
E
2答疑
[Sentence Correction]
试题详情
题目：
The Olympic Games helped to keep peace among the pugnacious states of the Greek world in that a sacred truce was proclaimed during the festival's month.
选项:
A、world in that a sacred truce was proclaimed during the festival's month
B、world, proclaiming a sacred truce during the festival's month
C、world when they proclaimed a sacred truce for the festival month
D、world, for a sacred truce was proclaimed during the month of the festival
E、world by proclamation of a sacred truce that was for the month of the festival
答案:
D
2答疑
[Critical Reasoning]
试题详情
题目：
A certain cultivated herb is one of a group of closely related plants that thrive in soil with high concentrations of metals that are toxic to most other plants. Agronomists studying the growth of this herb have discovered that it produces large amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert. Hence, the herb’s high histidine production must be the key feature that allows it to grow in metal-rich soils.
In evaluating the argument, it would be most important to determine which of the following?
In evaluating the argument, it would be most important to determine which of the following?
选项:
A、Whether the herb can thrive in soil that does not have high concentrations of the toxic metals
B、Whether others of the closely related group of plants also produce histidine in large quantities
C、Whether the herb’s high level of histidine production is associated with an unusually low level of production of some other amino acid
D、Whether growing the herb in soil with high concentrations of the metals will, over time, reduce their concentrations in the soil
E、Whether the concentration of histidine in the growing herb declines as the plant approaches maturity
答案:
B
2答疑
[Reading Comprehension]
试题详情
文章：
| Line | While the most abundant and dominant species |
| within a particular ecosystem is often crucial in | |
| perpetuating the ecosystem, a “keystone” species, | |
| here defined as one whose effects are much larger | |
| (5) | than would be predicted from its abundance, can |
| also play a vital role. But because complex species | |
| interactions may be involved, identifying a keystone | |
| species by removing the species and observing | |
| changes in the ecosystem is problematic. It might | |
| (10) | seem that certain traits would clearly define a species |
| as a keystone species; for example, | |
| Pisaster ochraceus is often a keystone predator | |
| because it consumes and suppresses mussel | |
| populations, which in the absence of this starfish | |
| (15) | can be a dominant species. But such predation on a |
| dominant or potentially dominant species occurs in | |
| systems that do as well as in systems that do not | |
| have species that play keystone roles. Moreover, | |
| whereas P. ochraceus occupies an unambiguous | |
| (20) | keystone role on wave-exposed rocky headlands, |
| in more wave-sheltered habitats the impact of | |
| P. ochraceus predation is weak or nonexistent, | |
| and at certain sites sand burial is responsible for | |
| eliminating mussels. Keystone status appears to | |
| (25) | depend on context, whether of particular |
| geography or of such factors as community | |
| diversity (for example, a reduction in species | |
| diversity may thrust more of the remaining species | |
| into keystone roles) and length of species | |
| (30) | interaction (since newly arrived species in particular |
| may dramatically affect ecosystems). |
题目：
Which of the following, if true, would most clearly support the argument about keystone status advanced in the last sentence of the passage (lines 24–31)?
选项:
A、A species of bat is primarily responsible for keeping insect populations within an ecosystem low, and the size of the insect population in turn affects bird species within that ecosystem.
B、A species of iguana occupies a keystone role on certain tropical islands, but does not play that role on adjacent tropical islands that are inhabited by a greater number of animal species.
C、Close observation of a savannah ecosystem reveals that more species occupy keystone roles within that ecosystem than biologists had previously believed.
D、As a keystone species of bee becomes more abundant, it has a larger effect on the ecosystem it inhabits.
E、A species of moth that occupies a keystone role in a prairie habitat develops coloration patterns that camouflage it from potential predators.
答案:
B
2答疑
[Sentence Correction]
试题详情
题目：
Researchers now regard interferon as not a single substance, but it is rather a biological family of complex molecules that play an important, though not entirely defined, role in the immune system.
选项:
答案:
C
2答疑
[Sentence Correction]
试题详情
题目：
In 1979 lack of rain reduced India's rice production to about 41 million tons, nearly 25 percent less than those of the 1978 harvest.
选项:
A、less than those of the 1978 harvest
B、less than the 1978 harvest
C、less than 1978
D、fewer than 1978
E、fewer than that of India's 1978 harvest
答案:
B
2答疑
[Sentence Correction]
试题详情
题目：
According to a study by the Carnegie Foundation for the Advancement of Teaching, companies in the United States are providing job training and general education for nearly eight million people, about equivalent to the enrollment of the nation's four-year colleges and universities.
选项:
A、equivalent to the enrollment ofthe equivalent of those enrolled in
B、equal to those who are enrolled in
C、as many as the enrollment of
D、as many as are enrolled in
答案:
E
0评分
445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
1497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
1686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
1461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
1041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
166460浏览
0评分
173574浏览
