【案例分析题】

Influenza
Influenza has been with US a long time.According to some Greek writers ______【51】medical history，the outbreak of 412B.C.was of influenza.The same has been suggested of the sickness______【52】swept through the Greek army attacking Syracuse in 395B.C.Flu is a disease that moves most quickly among people living in ______【53】conditions，hence，it is likely to attack armies.
______【54】the nineteenth century there were five widespread outbreaks（教材）of influenza.The last of the five______【55】in 1889and marked the beginning of the story of influenza in our time.______【56】the recent outbreak，it started in Asia.
For more than forty years before that outbreak，influenza had steadily______【57】and was believed to be dying out.A new group of outbreaks was______【58】by the great outbreak of 1889-1890and for the next quarter of a century flu remained a constant threat.
In April 1918flu broke out among American troops stationed in France.It quickly spread through all the______【59】but caused relatively few deaths.Four months later，however，a second outbreak started which______【60】to be a killer.It killed not only the old and already sick but also healthy young adults.It______【61】through every country in the world，only a few distant islands in the South Atlantic and the Pacific remaining ______【62】.It brought the life of whole countries to stop，food ______【63】stopped and work loss was very great.Before the great outbreak ended，it had killed at______【64】15million people.There after there have been several great outbreaks throughout the world.It is thus______【65】that influenza is a terrible infection that we have to pay more attention to.

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