2.x and y are real numbers and x+y＞1
15.Amy and Jed are among the 35 people,who are standing in a line,one behind the other,waiting to buy movie tickets.The number of people in front of Amy plus the number of people behind Jed is 24.If there are 15 people behind Amy,including Jed,how many people are in front of Jed?
6-6 Many fairy tales are complex narratives of wish fulfillment.They teach the reader that a struggle against severe difficulties in life is(i)_____,that it is an intrinsic part of human existence,and that if one does not(ii)_____,but steadfastly meets unexpected and often unjust hardships,one masters all obstacles and at the end(iii)_____. 美国留学GRE
31-6 For many years,Americans have had a love affair with ferryboats.Ferries are said to relieve our frayed nerves after we’ve stewed in bumper-to-bumper traffic,and conventional wisdom also says ferries(i)_____ congestion and air pollution by getting us out of cars.Unfortunately,this(ii)_____ notion recently has(iii)_____ several West Coast mayors,who have in consequence eagerly pursued the implementation of ferry service in their cities.
31-9 Individuals,governments,and companies show ample ability to _____ themselves by setting goals based on current conditions and then blindly following them even when those conditions change drastically.
44-1 The science of astronomy was begun by amateurs and today remains dependent on their contributions,which are incisive by virtue of being _____ by the a priori assumptions that often vitiate the work of professional research scientists.
74-1 Many legislators who helped Roosevelt shape the New Deal _____ the fact that emerging social problems affected every segment of the population;nonetheless,they often acted with a view to aiding only their own constituents.
83-6 The difficulty for nineteenth-century advocates of the claim that forests helped regulate climate was that their argument(i)_____ historical anecdote and observations.Proving the forest-climate link through verifiable and experimental scientific means rather than observation was(ii)_____ for these individuals,a situation that eventually led to the link(iii)_____ justifications for forest conservation.
88-6 Many historians of the ancient world are wary of sounding(i)_____.Write so much as a sentence and the temptation is immediately to(ii)_____ it.Even in cases when the sources for a given event are(iii)_____,uncertainties and discrepancies crop up everywhere.
96-5 The Golden Gates Bridge has been quite(i)_____ by most aesthetic and functional criteria.However,as a structure it has had some limitations.Shortly after it opened,its roadway proved to be(ii)_____ under certain wind conditions,so it was stiffened.The additional steel that provided that stiffening naturally added weight to the structure,and this made it(iii)_____ later to add a proposed rail system beneath the roadway.
116-6(i)______,we can safely infer causality by appealing to a set of general principles(Newtonian mechanics,for example)that are well understood and have been shown to apply in comparably straightforward circumstances.However,for the opposing class,which consists of(ii)______ systems like the global economy,human physiology,or the human mind itself,explanations of singular events are usually(iii)______,absent the requisite accounting for the intricate dynamics of such systems.
127-2 The development of junior high schools in American education was motivated by _____ rather than by pedagogical validity:these schools provided an efficient and inexpensive way to eliminate overcrowding in the high schools.
143-8 Motorcycle riders in London have discovered an ingenious,albeit ______ way of parking illegally without getting a ticket.
143-10 California’s building codes are more ______ than those elsewhere in the United States to ensure that structures are capable of protecting people from frequent seismic events.
Recent studies of the gender gap in the history of United States policies tend to focus on candidate choice rather than on registration and turnout.This shift in focus from gender inequality in political participation may be due to the finding in several studies of voting behavior in the United States that since 1980,differences in rates of registration and voting between men and women are not statistically significant after controlling for traditional predictors of participation.However,Fullerton and Stern argue that researchers have overlooked the substantial gender gap in registration and voting in the South.While the gender gap in participation virtually disappeared outside the South by the 1950s,substantial gender differences persisted in the South throughout the 1950s and 1960s,only beginning to decline in 1970s.
1.Select the sentence in the passage that offers a possible explanation for a trend.
2.According to the passage,which of the following is true about recent studies of the gender gap in the United States politics?
A.They accurately depict voter preference in the South prior to 1980.
B.They have been unduly influenced by changes in voter preferences.
C.They fail to recognize important factors affecting levels of voter participation.
D.They do not pay sufficient attention to the effect regional differences have on voter preference.
E.They are more concerned with the choices that male and female voters make than with the frequency with which they vote.
3.The author of the passage cites“several studies of voting behavior in the United States”to
A.suggest that rates of change in political participation have moderated
B.provide a possible explanation for a propensity among certain researchers
C.indicate an area of research that is particularly promising
D.speculate about the implications of a change
E.suggest that a particular area of study has not been very productive
4.The passage is primarily concerned with
A.establishing the chronology of a transition
B.discussing a perceived oversight
C.explaining the reasons for a change
D.evaluating an underlying assumption
E.confirming the merits of a claim
The crustaceans known as harpacticoids are very widespread in marine sediments,where they feed on microorganisms by ingesting the sediment particles to which the microorganisms adhere.Heavy metals,such as those found in industrial pollution,readily adhere to sediment particles.Harpacticoids are poisoned by heavy metals but are unaffected by most other pollutants.Therefore the concentration of harpacticoids in an area is a good indication of whether that marine environment contains heavy metals.
Which of the following is an assumption on which the argument relies?
A.Industrial pollution is the principal source of heavy metals in marine sediments.
B.Harpacticoids are the only crustaceans that feed on microorganisms by ingesting sediment particles.
C.Harpacticoids are more susceptible to poisoning by heavy metals than are other marine organisms.
D.The microorganisms that harpacticoids feed on are not killed by pollutants that are harmless to harpacticoids.
E.The microorganisms that harpacticoids feed on absorb heavy metals.
Astronomers have had difficulty accounting for certain planets discovered outside our solar system.They are called hot Jupiters because each is similar in mass to Jupiter,the largest solar-system planet,but orbits its parent star at a fraction of the distance at which Earth,let alone Jupiter,orbits the Sun.In the standard,solar-system-based theory of planetary formation,such a massive planet could not form so close to a star.So most attempts to explain a hot Jupiter’s existence envision it forming farther away,then migrating inward.According to one hypothesis,the planet’s gravitational field tugs on the protoplanetary disk of dust and gas from which it formed.The disk exerts its own gravitational tug,and this interplay of forces robs the planet of momentum in its orbital path,forcing it to spiral in toward the star.According to another hypothesis,the planet’s gravitational field is so strong that it creates a groove in the disk,partitioning it into inner and outer regions;the resulting gravitational interactions between the planet and these regions cause the planet to lose orbital momentum and spiral inward.Another question remains:what prevents the planet from continuing its spiral until it collides with the star?
1.The author of the passage mentions“Earth”primarily in order to
A.stress the massive size of a hot Jupiter
B.emphasize the proximity of a hot Jupiter to its parent star
C.imply that hot Jupiters are unlikely to harbor extraterrestrial life
D.point out differences between Earth and Jupiter with regard to their orbital distance from the Sun
E.illustrate how hot Jupiters might fit into the standard theory of planetary formation
2.Which of the following elements is part of one but not both of the hypotheses discussed in the passage?
A.an interplay of gravitational forces
B.a loss of orbital momentum
C.a protoplanetary disk composed of dust and gas
D.a protoplanetary disk divided into two regions.
3.It can be inferred from the passage that the“attempts”share which of the following goals?
A.to explain how a Jupiter-sized planet could form so close to its parent star.
B.to explain what prevents a hot Jupiter from colliding with its parent star.
C.to determine whether a hot Jupiter is formed from a protoplanetary disk of dust and gas.
D.to determine whether a hot Jupiter’s gravitational field is strong enough to create a groove in its protoplantary disk
E.to account for hot Jupiters in a way that is not inconsistent with the standard theory of planetary formation.