gre阅读练习每日一篇(四十五)

　　掌握了gre阅读里的长难句，到了实战演习的时候了。gre阅读练习每日一篇帮助gre考生循序渐进地进行练习和总结。希望gre考生在进行gre阅读练习时，也按着考试时候的时间规定自己的练习，这样才能有效果。

　　A serious critic has to comprehend the particular content, unique structure, and special meaning of a work of art. And here she faces a dilemma. The critic must recognize the artistic element of uniqueness that requires subjective reaction; yet she must not be unduly prejudiced by such reactions. Her likes and dislikes are less important than what the work itself communicates, and her preferences may blind her to certain qualities of the work and thereby prevent an adequate understanding of it. Hence, it is necessary that a critic develop a sensibility informed by familiarity with the history of art and aesthetic theory. On the other hand, it is insufficient to treat the artwork solely historically, in relation to a fixed set of ideas or values. The critics knowledge and training are, rather, a preparation of the cognitive and emotional abilities needed for an adequate personal response to an artworks own particular qualities.

　　17. According to the author, a serious art critic may avoid being prejudiced by her subjective reactions if she

　　 treats an artwork in relation to a fixed set of ideas and values

　　 brings to her observation a knowledge of art history and aesthetic theory

　　 allows more time for the observation of each artwork

　　 takes into account the preferences of other art critics

　　 limits herself to that art with which she has adequate familiarity

　　18. The author implies that it is insufficient to treat a work of art solely historically because

　　 doing so would lead the critic into a dilemma

　　 doing so can blind the critic to some of the artworks unique qualities

　　 doing so can insulate the critic from personally held beliefs

　　 subjective reactions can produce a biased response

　　 critics are not sufficiently familiar with art history

　　19. The passage suggests that the author would be most likely to agree with which of the following statements?

　　 Art speaks to the passions as well as to the intellect.

　　 Most works of art express unconscious wishes or desires.

　　 The best art is accessible to the greatest number of people.

　　 The art produced in the last few decades is of inferior quality.

　　 The meaning of art is a function of the social conditions in which it was produced.

　　20. The authors argument is developed primarily by the use of

　　 an attack on sentimentality

　　 an example of successful art criticism

　　 a critique of artists training

　　 a warning against extremes in art criticism

　　 an analogy between art criticism and art production

　　Viruses, infectious particles consisting of nucleic acid packaged in a protein coat , are difficult to resist. Unable to reproduce outside a living cell, viruses reproduce only by subverting the genetic mechanisms of a host cell. In one kind of viral life cycle , the virus first binds to the cells surface, then penetrates the cell and sheds its capsid. The exposed viral nucleic acid produces new viruses from the contents of the cell. Finally, the cell releases the viral progeny, and a new cell cycle of infection begins. The human body responds to a viral infection by producing antibodies: complex, highly specific proteins that selectively bind to foreign molecules such as viruses. An antibody can either interfere with a viruss ability to bind to a cell, or can prevent it from releasing its nucleic acid.

　　Unfortunately, the common cold , produced most often by rhinoviruses, is intractable to antiviral defense. Humans have difficulty resisting colds because rhinoviruses are so diverse, including at least 100 strains. The strains differ most in the molecular structure of the proteins in their capsids. Since disease-fighting antibodies bind to the capsid, an antibody developed to protect against one rhinovirus strain is useless against other strains. Different antibodies must be produced for each strain.

　　A defense against rhinoviruses might nonetheless succeed by exploiting hidden similarities among the rhinovirus strains. For example, most rhinovirus strains bind to the same kind of molecule on a cells surface when they attack human cells. Colonno, taking advantage of these common receptors, devised a strategy for blocking the attachment of rhinoviruses to their appropriate receptors. Rather than fruitlessly searching for an antibody that would bind to all rhinoviruses, Colonno realized that an antibody binding to the common receptors of a human cell would prevent rhinoviruses from initiating an infection. Because human cells normally do not develop antibodies to components of their own cells, Colonno injected human cells into mice, which did produce an antibody to the common receptor. In isolated human cells, this antibody proved to be extraordinarily effective at thwarting the rhinovirus. Moreover, when the antibody was given to chimpanzees, it inhibited rhinoviral growth, and in humans it lessened both the severity and duration of cold symptoms.

　　Another possible defense against rhinoviruses was proposed by Rossman, who described rhinoviruses detailed molecular structure. Rossman showed that protein sequences common to all rhinovirus strains lie at the base of a deep canyon scoring each face of the capsid. The narrow opening of this canyon possibly prevents the relatively large antibody molecules from binding to the common sequence, but smaller molecules might reach it. Among these smaller, nonantibody molecules, some might bind to the common sequence, lock the nucleic acid in its coat, and thereby prevent the virus from reproducing.

　　21. The primary purpose of the passage is to

　　 discuss viral mechanisms and possible ways of circumventing certain kinds of those mechanisms

　　 challenge recent research on how rhinoviruses bind to receptors on the surfaces of cells

　　 suggest future research on rhinoviral growth in chimpanzees

　　 defend a controversial research program whose purpose is to discover the molecular structure of rhinovirus capsids

　　 evaluate a dispute between advocates of two theories about the rhinovirus life cycle

　　22. It can be inferred from the passage that the protein sequences of the capsid that vary most among strains of rhinovirus are those

　　 at the base of the canyon

　　 outside of the canyon

　　 responsible for producing nucleic acid

　　 responsible for preventing the formation of delta-receptors

　　 preventing the capsid from releasing its nucleic acid

　　23. It can be inferred from the passage that a cell lacking delta-receptors will be

　　 unable to prevent the rhinoviral nucleic acid from shedding its capsid

　　 defenseless against most strains of rhinovirus

　　 unable to release the viral progeny it develops after infection

　　 protected from new infections by antibodies to the rhinovirus

　　 resistant to infection by most strains of rhinovirus

　　24. Which of the following research strategies for developing a defense against the common cold would the author be likely to find most promising?

　　 Continuing to look for a general antirhinoviral antibody

　　 Searching for common cell-surface receptors in humans and mice

　　 Continuing to look for similarities among the various strains of rhinovirus

　　 Discovering how the human body produces antibodies in response to a rhinoviral infection

　　 Determining the detailed molecular structure of the nucleic acid of a rhinovirus

　　25. It can be inferred from the passage that the purpose of Colonnos experiments was to determine whether

　　 chimpanzees and humans can both be infected by rhinoviruses

　　 chimpanzees can produce antibodies to human cell-surface receptors

　　 a rhinovirus nucleic acid might be locked in its protein coat

　　 binding antibodies to common receptors could produce a possible defense against rhinoviruses

　　 rhinoviruses are vulnerable to human antibodies

　　26. According to the passage, Rossmans research suggests that

　　 a defense against rhinoviruses might exploit structural similarities among the strains of rhinovirus

　　 human cells normally do not develop antibodies to components of their own cells

　　 the various strains of rhinovirus differ in their ability to bind to the surface of a host cell

　　 rhinovirus versatility can work to the benefit of researchers trying to find a useful antibody

　　 Colonnos research findings are probably invalid

　　27. According to the passage, in order for a given antibody to bind to a given rhinoviral capsid, which of the following must be true?

　　 The capsid must have a deep canyon on each of its faces.

　　 The antibody must be specific to the molecular structure of the particular capsid.

　　 The capsid must separate from its nucleic acid before binding to an antibody.

　　 The antibody must bind to a particular cell-surface receptor before it can bind to a rhinovirus.

　　 The antibody must first enter a cell containing the particular rhinovirus.