Information must be free from error means that the information must be perfectly accurate in all aspects.

There is only one wish realisable on the earth; only one thing that can be perfectly attained: Death. And from a variety of circumstances we have no one to tell us whether it be worth attaining.

A strange picture we make on our way to our chimaeras, ceaselessly marching, grudging ourselves the time for rest; indefatigable, adventurous pioneers. It is true that we shall never reach the goal; it is even more than probable that there is no such place; and if we lived for centuries and were endowed with the powers of a god, we should find ourselves not much nearer what we wanted at the end. O toiling hands of mortals! O unwearied feet, travelling ye know not whither! Soon, soon, it seems to you, you must come forth on some conspicuous hilltop, and but a little way further, against the setting sun, descry the spires of El Dorado. Little do ye know your own blessednes; for to travel hopefully is a better thing than to arrive, and the true success is to labour.

From the beginning, the idea of a finite universe ran into its own obstacle,

the apparent need for an edge, a problem that has only recently been grappled

with. Aristotle's argument, that the universe is finite, and that a boundary was

necessary to fix an absolute reference frame, held only until scientists wondered

(5) what happened at the far side of the edge. In other words, why do we not

redefine the "universe" to include that other side?

Riemann ingeniously replied by proposing the hypersphere, the three-

dimensional surface of a four-dimensional ball. Previously it was supposed that

the ultimate physical reality must be a Euclidean space of some dimension, and

(10) thus if space were a hypersphere, it would need to sit in a four-dimensional

Euclidean space that allows us to view it from the outside. But according to

Riemann, it would be perfectly acceptable for the universe to be a hypersphere

and not embedded in any higher-dimensional space; nature need not therefore

cling to the ancient notion. According to Einstein's powerful but limited theory

(15) of relativity, space is a dynamic medium that can curve in one of three ways,

depending on the distribution of matter and energy within it, but because we are

embedded in space, we cannot see the flexure directly but rather perceive it as

gravitational attraction and geometric distortion of images. Thus, to determine

which of the three geometries our universe has, astronomers are forced to

(20) measure the density of matter and energy in the cosmos, whose amounts appear

at present to be insufficient to force space to arch back on itself in "spherical"

geometry. Space may also have the familiar Euclidean geometry, like that of a

plane, or a "hyperbolic" geometry, like that of a saddle. Furthermore, the

universe could be spherical, yet so large that the observable part seems

(25) Euclidean, just as a small patch of the earth's surface looks flat.

We must recall that relativity is a purely local theory: it predicts the

curvature of each small volume of space--its geometry--based on the matter

and energy it contains, and the three plausible cosmic geometries are consistent

with many different topologies: relativity would describe both a torus and a

(30) plane with the same equations, even though the torus is finite and the plane is

infinite. Determining the topology therefore requires some physical

understanding beyond relativity, in order to answer the question, for instance,

of whether the universe is, like a plane, "simply connected", meaning there is

only one direct path for light to travel from a source to an observer. A simply

(35) connected Euclidean or hyperbolic universe would indeed be infinite--and seems

self-evident to the layman--but unfortunately the universe might instead be

"multiply-connected", like a torus, in which case there are many different such

paths. An observer could see multiple images of each galaxy and easily interpret

them as distinct galaxies in an endless space, much as a visitor to a mirrored

(40) room has the illusion of seeing a huge crowd, and for this reason physicists have

yet to conclusively determine the shape of the universe.

In the passage, the author is primarily concerned with

A．searching for an accurate method of determining whether the universe is finite or infinite

B．discussing problems and possibilities involved in providing a definite picture of the shape of the universe

C．declaring opposition to the notion that spherical geometry is a possible model for the shape of the universe

D．criticizing discredited theories about the possible topologies of the universe

E．refuting the idea that there is no way to tell whether the universe is finite and if so what shape it has

From the beginning, the idea of a finite universe ran into its own obstacle,

the apparent need for an edge, a problem that has only recently been grappled

with. Aristotle's argument, that the universe is finite, and that a boundary was

Line necessary to fix an absolute reference frame, held only until scientists wondered

(5) what happened at the far side of the edge. In other words, why do we not

redefine the "universe" to include that other side?

Riemann ingeniously replied by proposing the hypersphere, the three-

dimensional surface of a four-dimensional ball. Previously it was supposed that

the ultimate physical reality must be a Euclidean space of some dimension, and

(10) thus if space were a hypersphere, it would need to sit in a four-dimensional

Euclidean space that allows us to view it from the outside. But according to

Riemann, it would be perfectly acceptable for the universe to be a hypersphere

and not embedded in any higher-dimensional space; nature need not therefore

cling to the ancient notion. According to Einstein's powerful but limited theory

(15) of relativity, space is a dynamic medium that can curve in one of three ways,

depending on the distribution of matter and energy within it, but because we are

embedded in space, we cannot see the flexure directly but rather perceive it as

gravitational attraction and geometric distortion of images. Thus, to determine

which of the three geometries our universe has, astronomers are forced to

(20) measure the density of matter and energy in the cosmos, whose amounts appear

at present to be insufficient to force space to arch back on itself in "spherical"

geometry. Space may also have the familiar Euclidean geometry, like that of a

plane, or a "hyperbolic" geometry, like that of a saddle. Furthermore, the

universe could be spherical, yet so large that the observable part seems

(25) Euclidean, just as a small patch of the earth's surface looks flat.

We must recall that relativity is a purely local theory: it predicts the

curvature of each small volume of space-its geometry-based on the matter

and energy it contains, and the three plausible cosmic geometries are consistent

with many different topologies: relativity would describe both a torus and a

(30) plane with the same equations, even though the torus is finite and the plane is

infinite. Determining the topology therefore requires some physical

understanding beyond relativity, in order to answer the question, for instance,

of whether the universe is, like a plane, "simply connected", meaning there is

only one direct path for light to travel from a source to an observer. A simply

(35) connected Euclidean or hyperbolic universe would indeed be infinite-and seems

self-evident to the layman-but unfortunately the universe might instead be

"multiply-connected", like a torus, in which case there are many different such

paths. An observer could see multiple images of each galaxy and easily interpret

them as distinct galaxies in an endless space, much as a visitor to a mirrored

(40) room has the illusion of seeing a huge crowd, and for this reason physicists have

yet to conclusively determine the shape of the un

A．searching for an accurate method of determining whether the universe is finite or infinite

B．discussing problems and possibilities involved in providing a definite picture of the shape of the universe

C．declaring opposition to the notion that spherical geometry is a possible model for the shape of the universe

D．criticizing discredited theories about the possible topologies of the universe

E．refuting the idea that there is no way to tell whether the universe is finite and if so what shape it has

A、precisebut irrelevant

B、imprecisebut irrelevant

C、imprecisebut relevant

D、Allof these answers are correct

The statue would be perfect but for a few small ________ in its be.

A) mistakes

B) weaknesses

C) flaws

D) errors

The work by John Battelle would be perfected if appropriate consideration is given to ______.

A．the relationship between internet research and its potential future development

B．secretive dictatorships and Hollywood celebrities under control

C．the disappointments in Google and its rivals in respects to geeky concepts

D．companies' interests in Google at the moment when the world's economy is booming

The party was perfectly organized and I enjoyed every minute of it. And I am very grateful for this nice arrangement.(英译汉)

In a perfectly free and open market economy, the type of employer—government or private—should have little or no impact on the earnings differentials between women and men. However, if there is discrimination against one sex, it is unlikely that the degree of discrimination by government and private employers will be the same. Differences in the degree of discrimination would result in earnings differentials associated with the type of employer. Given the nature of government and private employers, it seems most likely that discrimination by private employers would be greater. Thus, one would expect that, if women are being discriminated against, government employment would have a positive effect on women's earnings as compared with their earnings from private employment. The results of a study by Fuchs support this assumption. Fuchs' results suggest that the earnings of women in an industry composed entirely of government employees would be 14.6 percent greater than the earnings of women in an industry composed exclusively of private employees, other things being equal.

In addition, both Fuchs and Sanborn have suggested that the effect of discrimination by consumers on the earnings of self-employed women may be greater than the effect of either government or private employer discrimination on the earnings of women employees. To test this hypothesis, Brown selected a large sample of white male and female workers from the 1970 census and divided them into three categories: private employees, government employees, and self-employed. (Black workers were excluded from the sample to avoid picking up earnings differentials that were the result of racial disparities.) Brown's research design controlled for education, labor-force participation, mobility, motivation, and age in order to eliminate these factors as explanations of the study's results. Brown's results suggest that men and women are not treated the came by employers and consumers. For men, self-employment is the highest earnings category, with private employment next, and government lowest. For women, this order is reversed.

One can infer from Brown's results that consumers discriminate against self-employed women. In addition, self-employed women may have more difficulty than men in getting good employees and may encounter discrimination from suppliers and from financial institutions.

Brown's results are clearly consistent with Fuchs' argument that discrimination by consumers has a greater impact on the earnings of women than does discrimination by either government or private employers. Also, the fact the women do better working for government than for private employers implies that private employers are discriminating against women. The results do not prove that government does not discriminate against women. They do, however, demonstrate that if government is discriminating against women, its discriminating is not having as much effect on women's earnings as is discrimination in the private sector.

The passage mentions all of the following difficulties that self-employed women may encounter EXCEPT ______.

A．discrimination from consumers and suppliers

B．discrimination from financial institutions

C．problems from financial institutions

D．problems in obtaining government assistance

In a perfectly free and open market economy, the type of employer—government or private—should have little or no impact on the earnings differentials between women and men. However, if there is discrimination against one sex, it is unlikely that the degree of discrimination by government and private employers will be the same. Differences in the degree of discrimination would result in earnings differentials associated with the type of employer. Given the nature of government and private employers, it seems most likely that discrimination by private employers, would be greater. Thus, one would expect that, if women are being discriminated against, government employment would have a positive effect on women's earnings as compared with their earnings from private employment. The results of a study by Fucks' support this assumption. Fucks' results suggest that the earnings of women in an industry composed entirely of government employees would be 14.6 percent greater than the earnings of women in an industry com- posed exclusively of private employees, other things being equal.

In addition, both Fuchs and Sanborn have suggested that the effect of discrimination by consumers on the earnings of self-employed women may be greater than the effect of either government or private employer discrimination on the earnings of women employees. To test this hypothesis. Brown selected a large sample of white male and female workers from the 1970 census and divided them into three categories: private employees, government employees, and self-employed. (Black workers were excluded from the sample to avoid picking up earnings differentials that were the result of racial disparities.) Brown' s research design controlled for education, labor-force participation, mobility, motivation, and age in order to eliminate these factors as explanations of the study' s results. Brown's results suggest that men and women are not treated the same by employers ad consumers. For men, self-employment is the highest earnings category, with private employment next, and government lowest. For women, this order is reversed.

One can infer from Brown's results that consumers discriminate against self-employed women, In addition, self-employed women may have more difficulty than men in getting good employees and may encounter discrimination from suppliers and from financial institutions.

Brown's results are clearly consistent with Fuchs' argument that discrimination by consumers has a greater impact on the earnings of women than does discrimination by either government or private employers. Also, the fact the women do better working for government than for private employers implies that private employers are discriminating against women. The results do not prove that government does not discriminate against women. They do, however, demonstrate that if government is discriminating against women, its discriminating is not having as much effect on women's earnings as is discrimination in the private sector.

The passage mentions all of the following as difficulties that self-employed women may encounter EXCEPT ______.

A．discrimination form. consumers and suppliers

B．discrimination from financial institutions

C．problems in obtaining good employees

D．problems in obtaining government assistance