There is a joke among flu researchers: “If you've seen one flu season, you've se

There is a joke among flu researchers:“If you've seen one flu season, you've seen one flu season.” The joke is aboutthe unpredictable nature of the flu virus．Every year it looks different, and every strain(类型) follows itsown pattern — it's the reason why new strains like H1N1 are extremely difficultto predict.

Dr．Michael Osterholm is a former adviser tothe U.S．Departmentof Health and Human Services．“Iknow less about influenza today than I did 10 years ago,” he says in a jokingway．“Every stonewe've turned over, we get more questions.”

The flu rectums every season and theworld experiences terrible pandemics (全国或全世界范围流行的疾病), but researchers still donot understand why some strains infect people and others do not; they are notentirely sure about how the flu is transmitted; nor do they understand why somepatients become seriously ill while others develop mild symptoms (症状)．As a result, when a new strain shows up —like H1N1 — they often have little information to fall back on, and thelessons of previous pandemics are only somewhat helpful．While researchers are stillputting together a complete picture of H1N1, for example, its most strikingdifference with the seasonal flu is that the elder1y are not the most vulnerable(易受攻击的)population.

Influenza's unpredictable nature makes ita moving target for researchers, says researcher Allison Aiello at theUniversity of Michigan．“Evenif we had complete seasonal flu data from the past, it wouldn't be much helpfulfor a new strain of influenza,” she explains.

Whi1e researchers are frustrated by theholes in their knowledge, they say, however, that the pub1ic--health communityis generally doing a very good job responding to H1N1 with seasonal flu datathat do exist．Studyinginfluenza, says Osterholm, is “like looking through the windows of a house youcan't get into because the door is locked.” Gathering the data researchers dohave is like “looking through the windows to get a pretty good picture of whatthe inside looks like.”

One thing researchers do know for sure:the best way for people to protect against H1N1 is to get the vaccine once itbecomes available to them.

1.Whatdo we learn about H1N1 from the passage?

  A．In fact it is not a kind ofinfluenza virus.

  B．It is quite possible to predictit in theory.

  C．Old people are more likely tocontract it than kids.

  D．Receiving vaccines will beeffective to protect against it.

2.Theunderlined phrase “fall back on” in Para．3 probably means      .

  A．rely on                 B．pass on               C．col1ect            D．exchange

3.Whatdo we know about previous seasonal flu data?

  A．It is useless to study them.           

  B．It is still necessary to studythem.

  C．They are misleading most of thetime.

  D．They are much more helpful thanexpected.

4.Whichof the following could be the best title for the passage?

  A．Outbreaks of the flu                             B．Symptoms of the flu

  C．Mysteries of the flu                              D．Risks of the flu

试题答案

【答案】

1.D

2.A

3.B

4.C