GRE陈虎平阅读36套-19-智课网.pdf

智课网GRE 备考资料 Exercise 19 The common cold, produced most often by rhinoviruses, 1. It can be inferred from the passage that a cell is intractable to antiviral defense. A defense against lacking delta-receptors will be rhinoviruses might nonetheless succeed by exploiting (A) unable to prevent the rhinoviral nucleic acid hidden similarities among the rhinovirus strains. For from shedding its capsid example, most rhinovirus strains bind to the same kind of (B) defenseless against most strains of rhinovirus molecule (delta-receptors) on a cell‘s surface when they (C) unable to release the viral progeny it develops attack human cells. Colonno, taking advantage of these after infection common receptors, devised a strategy for blocking the (D) protected from new infections by antibodies attachment of rhinoviruses to their appropriate receptors. to the rhinovirus Rather than fruitlessly searching for an antibody that would (E) resistant to infection by most strains of bind to all rhinoviruses, Colonno realized that an antibody rhinovirus binding to the common receptors of a human cell would prevent rhinoviruses from initiating an infection. Because 2. It can be inferred from the passage that the purpose human cells normally do not develop antibodies to of Colonno ‘s experiments was to determine whether components of their own cells, Colonno injected human (A) chimpanzees and humans can both be infected cells into mice, which did produce an antibody to the by rhinoviruses common receptor. In isolated human cells, this antibody (B) chimpanzees can produce antibodies to human proved to be extraordinarily effective at thwarting the