Question

    The flu season arrives so predictably, and affects so many of us, that it’s hard to believe that scientists have had very little idea why cold weather helps germs to spread.

Worldwide, up to five million people catch the illness each flu season, and around a quarter of a million die from it. Part of its power comes from the fact that the virus changes so quickly that the body is hardly prepared. “The antibodies we’ve built up no longer recognize the virus – so we lose our immunity,” says Jane Metz at the University of Bristol. It also makes it harder to develop effective vaccines, and even if one comes out, governments often fail to persuade enough people to take it up.

The hope is that by understanding better why flu spreads in winter, but naturally fades in summer, doctors could find simple measures to stop its spread.

Previous theories had centred on our behaviour. We spend more time indoors in the winter, meaning that we’re in closer contact with other people who may be carrying germs.

Another popular idea concerned our physiology(生理机制): the cold weather weakens your body’s defenses against infection. In winter, without much sunlight, we may run low on Vitamin D, which helps power the body’s immune system. Moreover, when we breathe in cold air, the blood vessels in our nose shrink, which affects the normal function of white blood cells, allowing viruses to slip past our defenses unnoticed.

While such factors both play some role, analyses suggested another ignored cause may have been lying invisible in the air that we breathe. Thanks to the laws of thermodynamics(空气热力学), cold air can carry less water vapor before it reaches the “dew point” and falls as rain. So while the weather outside may seem wetter, the air itself is drier as it loses the moisture. And researches in the past few years has shown that these dry conditions seem to offer the perfect environment for the flu virus to flourish.

In wetter air, the epidemic struggles to build strength, while in drier conditions it spreads like wildfire. And comparing 30 years’ climate records with health records, Jeffrey Shaman at Columbia University found that flu epidemics almost always followed a drop in air humidity.

1.What can we infer from the second paragraph ?

A.We lose immunity due to the absence of our antibodies.

B.The antibodies fail to function due to variation of virus.

C.Government should come up with better ways to persuade people.

D.One in four of the infected die from the influenza each flu season.

2.What is the purpose of understanding better why flu spreads in winter?

A.To help develop effective vaccine.

B.To seek ways to treat people infected with flu.

C.To figure out ways to cut off its transmission.

D.To explore how to defend our immune system.

3.In what weather condition a flu epidemic is more likely to occur ?

A.Destroying bodies’ immune system.

B.Powering our bodies’ immune system.

C.Killing numerous viruses that we take in.

D.Stopping us acquiring enough Vitamin D.

4.What is the best title of the passage?

A.Ways to prevent infection of flu B.Flu-A disease not so hard to prevent

C.A predictable flu season D.Why germs spread in winter

Answer

1.B

2.C

3.D

4.D

【解析】

本篇是说明文，文章介绍了流感在冬天传播的原因。

1.

推理判断题。根据第二段“Part of its power comes from the fact that the virus changes so quickly that the body is hardly prepared. “The antibodies we’ve built up no longer recognize the virus – so we lose our immunity,” says Jane Metz at the University of Bristol.” 流感病毒的变异速度极快，往往令我们的身体对下一季的菌株措不及防。布里斯托大学的简·梅茨(Jane Metz)说‘我们体内的抗体已经无法识别这些病毒——所以我们失去了免疫力’。所以从第二段可以看出，我们身体的抗体由于病毒的变化多样而无法运行。故选B项。

2.

细节理解题。根据第三段“The hope is that by understanding better why flu spreads in winter, but naturally fades in summer, doctors could find simple measures to stop its spread.” 倘若能够更好地了解流感为什么在冬季流行，到了夏季却销声匿迹，医生便可找到简单的方法来抑制它的传播。所以为了更好地了解流感为什么在冬季流行的目的是为了抑制流感传播。故选C项。

3.

推理判断题。根据第五段“In winter, without much sunlight, we may run low on Vitamin D, which helps power the body’s immune system. Moreover, when we breathe in cold air, the blood vessels in our nose shrink, which affects the normal function of white blood cells, allowing viruses to slip past our defenses unnoticed.” 由于冬天日照时间缩短，我们体内的维生素D含量可能降低。由于维生素D有助于加强我们的免疫系统，因此这种营养物质的缺乏导致我们更容易患传染病。所以阻止我们获得足够维D的天气更容易爆发流感。故选D项。

4.

主旨大意题。根据文章第一段“The flu season arrives so predictably, and affects so many of us, that it’s hard to believe that scientists have had very little idea why cold weather helps germs to spread.” 流感季节总是很有规律，而且总会影响很多人。但即便如此，科学家对于寒冷的天气为什么有助于流感病菌的传播却知之甚少，这着实令人意外。文章首段引出主题，整篇文章都是围绕着为什么细菌在冬天传播。所以短文的最佳标题为“为什么细菌在冬天传播”。故选D项。