Among the devastating consequences of AIDS has (21) its epidemic spread in the developing world. The disease has caused (22) suffering, debilitation, loss of life and disruption of family, social and economic (23) Because of the considerable expense and logistical difficulty in providing antiviral drugs to populations (24) with the Human Immunodeficiency Virus (25) the world, the biomedical community is looking towards vaccines to help solve this compelling problem. The search for an AIDS vaccine began more than 15 years ago with great (26) and high expectations. With the (27) of the Human Immunodeficiency Virus (HIV) as the cause of AIDS, it seemed that a (28) would follow closely behind. But despite a large concerted effort, the problem has proven more difficult than (29) , and progress has not (30) the (31) hopes. Here I review the (32) scientific obstacles confronting the development of an effective HIV vaccine, and I consider (33) strategies to overcome these obstacles. It i
A. surpassed
B. out-balanced
C. matched
D. rivaled
Among the devastating consequences of AIDS has (21) its epidemic spread in the developing world. The disease has caused (22) suffering, debilitation, loss of life and disruption of family, social and economic (23) Because of the considerable expense and logistical difficulty in providing antiviral drugs to populations (24) with the Human Immunodeficiency Virus (25) the world, the biomedical community is looking towards vaccines to help solve this compelling problem. The search for an AIDS vaccine began more than 15 years ago with great (26) and high expectations. With the (27) of the Human Immunodeficiency Virus (HIV) as the cause of AIDS, it seemed that a (28) would follow closely behind. But despite a large concerted effort, the problem has proven more difficult than (29) , and progress has not (30) the (31) hopes. Here I review the (32) scientific obstacles confronting the development of an effective HIV vaccine, and I consider (33) strategies to overcome these obstacles. It i
A. majority
B. primary
C. principal
D. premier
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