2. 职称英语
  3. Although we already know a great deal about influenza, it is difficult for e

Although we already know a great deal about influenza, it is difficult for e

游客2023-08-26  72
问题     Although we already know a great deal about influenza, it is difficult for epidemiologists(流行病学家), who study infectious disease, to【C1】______when and where the next flu epidemic will occur, and how【C2】______it will be. There are three kinds of influenza virus, known as A, B and C. Influenza C virus is relatively stable and causes mild【C3】______that do not spread far through the population. The A and B types are【C4】______, and are responsible for the epidemics that cause frequent concern. Following any virus attack, the human body builds up antibodies which confer(给予)immunity to that strain of virus, but a virus with the capacity to change its character is able to bypass this【C5】______. Variability is less developed in the influenza B virus, which affects only human beings. An influenza B virus may cause a widespread epidemic but will have little effect if【C6】______into the same community soon afterwards, since nearly everyone will have built up antibodies and will be immune. The influenza A virus, which【C7】______affects animals, is extremely unstable and is responsible for some of the worst outbreaks of the disease, such as the unparalleled pandemic, or world epidemic. Accurate prediction is difficult because of the complication of the【C8】______. A particular virus may be related to one to which some of the population have【C9】______involved immunity. The extent to which it will spread will depend on factors such as its own strength, or virulence, the ease with which it can be【C10】______and the strength of the opposition it encounters. Scientists, however, have a reliable general picture of the world situation, according to which we may take some precautions.
A)partially I)epidemics
B)guess J)also
C)factors K)attacks
D)equally L)introduced
E)generally M)unstable
F)protection N)infections
G)transmitted 0)predict
H)severe [br] 【C1】
选项
答案 O
解析 此处应填动词。此处是it is…for sb．to do sth．结构。when and where the．．．will occur这一将来时态的句子表明，科学家们对未来事情的判断应该是一种“推测”，选O)predict。B)guess一般表示毫无根据的猜测，故排除。
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