首页
登录
职称英语
The timing of flu season is a little hard to predict. Part of what makes it
The timing of flu season is a little hard to predict. Part of what makes it
游客
2025-03-03
9
管理
问题
The timing of flu season is a little hard to predict. Part of what makes it unpredictable is that scientists still don’ t understand exactly why we have one at all. There have been lots of theories:
One theory is that people spend more time indoors, with the windows closed, breathing each other’ s air. Other scientists have argued that cold of winter weakens our immune systems. A third theory is that the flu virus lives in the cold, dry air, but suffers in the warm, humid air.
For a while, scientists had a hard time testing these theories: they needed to run experiments, but researchers aren’ t allowed to infect humans with illnesses, and most lab animals aren’t affected by the flu the same way people are.
In 2007, a medical researcher named Peter Palese found an 80-year-old journal article that reported that guinea pigs (豚鼠)get infected and pass on the flu just like humans.
Palese decided to test Theory 3. The research team led by Palese ran several experiments and in each experiment, they injected half the guinea pigs with influenza A (the common flu), and put them in a box next to a box of uninfected animals.
At a temperature of 41 degrees, all four of the exposed guinea pigs caught the flu, but when Palese repeated the experiment at 68 degrees, only one of the animals was infected. And when he ran the test at 86 degrees, none of the exposed animals got sick.
The researchers also ran experiments where they varied the humidity in the room but kept the temperature constant: the drier the air, they found, the more animals got sick.
Palese’ s study showed that the influenza virus does spread more effectively in cold, dry air. [br] The purpose of the writer is to______.
选项
A、introduce a new flu theory
B、report a test on one flu theory
C、compare the various flu theories
D、point out a new approach to flu study
答案
B
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3980439.html
相关试题推荐
LittleJohncaughta________fishthismorning.A、aliveB、aloneC、lonelyD、living
______carewouldhavepreventedit.A、AfewB、AlittleC、FewD、LittleB本题考查形容词用法
SpeakerA:Canyoucomedownalittleforthiswatch?SpeakerB:________A、Yes,w
Mary:Yourlittleboyhasdoneagoodjobatschool.Eva:________A、Yes,youare
Itisdifficultforustoexplainphenomenathatwehavelittleor________dire
Whenshedoessomething,Mrs.Brownfeelsthatherlittlechildisalways______.
Itisdifficultforustoexplainphenomenathatwehavelittleor______direct
Thetimingoffluseasonisalittlehardtopredict.Partofwhatmakesit
Thetimingoffluseasonisalittlehardtopredict.Partofwhatmakesit
Whenaskedwhyhehadbeenabsent,littleFrank______agoodexcuse.A、caughtupw
随机试题
[originaltext]Weoftenpassonlittlebitsofinformationtoourchildren,
[img]2018m9s/ct_etoefz_etoeflistz_201808_0032[/img][br]Accordingtotheprofes
任何语言,包括诗的语言在内,都应该力求用最经济的方式,表达最丰富的内容。到了有话非说不可的时候,说出的话才能动人。否则内容空虚,即便用了最伟大的字眼和词
Accordingtothepassage,thewriteroftheletterisfrom______.[br]"Iwask
[originaltext]Duringastateofdeeprelaxation,severalphysiologicalchan
[originaltext]M:I’mthinkingaboutwhethertotellthatstoryaboutJoeatthe
【教学过程】 (一)情境导入 同学们假设我们写了一首新的乐曲,要把它交给唱片公司,有两种方式:把这首乐曲弹奏出来并录制在磁带上或者把这首乐曲的乐谱写下来
2、安规对工作许可人规定的安全责任有哪些?《变电安规》6.3.11.3
有“乐圣”之称的作曲家是() A.李斯特 B.莫扎特 C.贝多芬 D
根据深圳证券交易所《资金申购上网定价公开发行股票实施办法》和上海证券交易所《沪市
最新回复
(
0
)