Question

    Airborne dust is normally seen as an environmental problem, but the lack of it is making air pollution over China considerably worse.

A new study suggests less dust means more solar radiation hits the land surface,which reduces wind speed. That lack of wind in turn leads to an accumulation of air pollution over heavily populated parts of China. The researchers found that reduced dust levels cause a 13% increase in human-made pollution in the region.

Hundreds of millions of people across China continue to be impacted by air pollution from factories and coal-fl red power plants. Studies suggest that the dirty、air contributes to 1.6 million deaths a year, about 17% of all mortalities. But this new research says that the human-induced pollution is being made worse or better by naturally occurring dust that blows in from the Gobi desert. Using models to simulate 150 years of wind and dust patterns in the region, the researchers found that the dust deflects significant amounts of sunlight. Without it, more heat from the Sun hits the land. Differences in the temperatures between land and sea cause the winds to blow. Without the dust, the land warms up more and that changes the temperature differential with the sea leading to weaker breezes - and more air pollution.

“There are two dust sources. One is the Gobi and the other is the highlands of north-west China, but we found the Gobi had much more influence," said lead author Yang Yang, from the Pacific Northwest National Laboratory in Washington State, US. “Less dust in the atmosphere causes more solar radiation to reach the surface. It weakens the temperature difference between the land and the sea and impacts the circulation of the winds and causes a stagnation over eastern- China and that causes an accumulation of air pollution.”

Another study has recently shown a link between declining Arctic sea ice and a major air pollution event in China. The authors of the new study believe that both theories could be true.

“Our study has the same mechanism: the weakening of winds causes more pollution, and what is behind this needs to be studied/ said Yang Yang, “We have two views on this kind of weakening of wind. They found the sea ice, we found the dust-wind interaction can also lead to weakening of the wind. I think both of them are important.”

The researchers believe that the study may inform broader questions about how natural human-created aerosols interact.

Many parts of the world, in addition to China, are now suffering from increased levels of air pollution and understanding how dust, winds and emissions work together may help limit some of the worst impacts of dirty air.

One of the key lessons from this study is that the absence of dusty conditions could mean the air you are breathing is worse for you, not better.

1.According to the new study, the formation of air pollution over heavily populated parts of China is due to_________.

A.the accumulation of dust B.the shortage of wind

C.the high level of living standards D.the rise of temperature

2.Whats the right sequence of cause and effect leading to the air pollution?

①the worse circulation of the winds

②more heat from the sun

③lessening temperature between the land and the sea

④less dust

⑤a worse stagnation

A.④②③①⑤ B.①④②⑤③

C.④①③②⑤ D.①⑤②④③

3.What might Yang Yang agree with?

A.Lack of dust from the highlands of north-west China means we can breathe better air.

B.There is little connection between declining Arctic sea ice and air pollution in China.

C.Declining Arctic sea ice and dust-wind interaction can cause weakening of the wind.

D.The interaction between dust, winds and emissions can worse dusty conditions.

Answer

1.B

2.A

3.C

【解析】

本文是一篇科普说明文。文章介绍了一项新的研究，即尘埃减少可能意味着空气会变得更糟，而不是更好。

1.细节理解题。根据文章第二段“That lack of wind in turn leads to an accumulation of air pollution over heavily populated parts of China.( 风的缺乏反过来导致中国人口过多地区空气污染的累积。)”可知，中国人口稠密地区空气污染的形成是由于风力不足。故选B。

2.细节理解题。根据文章第三段“Without the dust, the land warms up more and that changes the temperature differential with the sea leading to weaker breezes - and more air pollution. (没有了沙尘，陆地温度上升更多，从而改变了与海洋的温差，导致微风减弱，空气污染加重。)”可知，导致空气污染的正确因果顺序是④②③①⑤。故选A。

3.推理判断题。根据文章第六段中杨阳的话“They found the sea ice, we found the dust-wind interaction can also lead to weakening of the wind. (他们发现了海冰，我们发现沙尘暴的相互作用也会导致风的减弱。)”可知，杨阳认为北极海冰的减少和沙尘暴的相互作用会导致风力减弱。故选C。