AIDS threatens not only lives but also-in poor countries - economic development. By【C1】______mainly at adults 20 to 49 years old, AIDS robs these societies【C2】______some of their most productive citizens. Ignorance and fear of the disease can disrupt families and communities and may even【C3】______political relations between nations. Because AIDS is a worldwide epidemic(传染病，流行病), nothing【C4】______than a worldwide effort can control and perhaps some day wipe the disease. Governments must【C5】______by fully informing their citizens【C6】______the epidemic and, most important, by telling people【C7】______actions they can take to prevent infection(感染). Public health agencies must also insure that blood transfusions(输血)and【C8】______are safe. Those already infected should receive【C9】______attention so they do not spread the virus to others. 【C10】______, the U. S. government has committed more than two billion dollars to fight【C11】______AIDS in 1989 - including more than 600 million dollars for research. The screening of blood【C12】______has already ensured the safety of blood supplies in the U. S. , and American military personnel are required to take【C13】______blood tests. Public health groups have carried【C14】______AIDS education programs aimed particularly at homosexuals,【C15】______addicts, and others whose behavior. makes them highly susceptible(易受影响的)【C16】______the virus. U. S. government agencies are also【C17】______public health authorities throughout the developing world in their efforts to【C18】______the spread of the AIDS virus and to treat those afflicted with the disease.【C19】______the rapid spread of the disease and the number of people now infected, the battle against AIDS will be difficult to win. But it's a battle the world cannot【C20】______to lose. 【C1】