考博习题练习

A．moving
B．enforcing
C．strengthening
D．relieving
【单选题】： A     B     C     D  

第2题：Paul is an ______ worker, and rarely does well in examinations. However he often refuses our help. A．errant B．erroneous C．erratic D．exotic

【单选题】： A     B     C     D

第3题：When she ______, she could not for a moment recognize her surroundings. A．came to B．came off C．came through D．came over

【单选题】： A     B     C     D

第4题：The antigen-antibody immunological reaction used to be regarded as typical of immunological responses.Antibodies are proteins synthesized by specialized cells called plasma cells, which are funned by lymphocytes (cells from the lymph system when an antigen, a substance foreign to the organism’s body, comes in contact with lymphocytes. Two important manifestations of antigen- antibody immunity are lysis, the rapid physical rupture of antigenic cells and the liberation of their contents into the surrounding medium, and phagocytosis, a process in which antigenic particles are engulfed by and very often digested by macrophages and polymorphs. The process of lysis is executed by a complex and unstable blood constituent known as complement, which will not work unless it is activated by a specific antibody; the process of pbagocytosis is greatly facilitated when the particles to be engulfed are coated by a specific antibody directed against them. The reluctance to abandon this hypothesis, however well it explains specific processes, impeded new research, and for many years antigens and antibodies dominated the thoughts of immunologists so completely that those immunologists overlooked certain difficulties. Perhaps the primary difficulty with the antigen-antibody explanation is the informational problem of how an antigen is recognized and how a structure exactly complementary to it is then synthesizeD、When molecular biologists discovered, moreover, that such information cannot flow from protein to protein, hut only from nucleic acid to protein, the theory that an antigen itself provided the mold that directed the synthesis of an antibody had to be seriously qualifieD、 The attempts at qualification and the information provided by research in molecular biology led scientists to realize that a second immunological reaction is mediated through the lymphocytes that are hostile to and bring about the destruction of the antigen. This type of immunological response is called cell- mediated immunity. Recent research in cell-mediated immunity has been concerned not only with the development of new and better vaccines, but also with the problem of transplanting tissues and organs from one organism to another, for although circulating antibodies play a part in the rejection of transplanted tissues, the primary role is played by cell-mediated reactions.During cell-mediated responses, receptor sites on specific lymphoeytes and surface antigens on the foreign tissue cells form a complex that binds the lymphocytes to the tissue. Such lymphocytes do not give rise to antibody- producing plasma cells but themselves bring about the death of the foreign-tissue cells, probably by secreting a variety of substances, some of which are toxic to the tissue cells and some of which stimulate increased phagocyte activity by white blood cells of the macrophage type.Cell-mediated immunity also accounts for the destruction of intracellular parasites. The author most probably believes that the antigen-antibody theory of immunological reaction______. A、is wrong B．was accepted without evidence C．is unverifiable D．is a partial explanation

【单选题】： A     B     C     D

第5题：OnApril 20, 2000, inAccra, Ghana, the leaders of six WestAfrican countries declared their intention to proceed to monetary union among the non-CF A、franc countries of the region by January 2003, as a first step toward a wider monetary union including all theECOWAS countries in 2004. The six countries (71) themselves to reducing central bank financing of budget deficits (72) 10 percent of the previous year’s government (73) ; reducing budget deficits to 4 percent of the second phase by 2003; creating aConvergenceCouncil to help (74) macroeconomic policies; and (75) up a common central bank. Their declaration (76) that, "Member States (77) the need (78) strong political commitment and (79) to (80) all such national policies (81) would facilitate the regional monetary integration process. The goal of a monetary union inECOWAS has long been an objective of the organization, going back to its formation in 1975, and is intended to (82) a broader integration process that would include enhanced regional trade and (83) institutions. In the colonial period, currency boards linked sets of countries in the region. (84) independence, (85) , these currency boards were (86) , with the (87) of theCF A、franc zone, which included the francophone countries of the region.Although there have been attempts to advance file agenda ofECOWAS monetary cooperation, political problems and other economic priorities in several of the region’s countries have to (88) inhibited progress.Although some problems remain, the recent initiative has been bolstered by the election in 1999 of a democratic government and a leader who is committed to regional (89) in Nigeria, the largest economy of the region, raising hopes that the long-delayed project can be (91) . A、building B、setting C、founding D、erecting

【单选题】： A     B     C     D