A
Wind turbines (涡轮) and solar panels that generate electricity are examples of “green” technology.A new study finds that such renewable energy might be green in another sense.Large collections of those turbines or solar panels appear capable of bringing rains to the desert and would allow more plants to grow.
Building large wind or solar farms just to study their question was not an option.It would be too costly.So experts Kalnay and Safa developed a model of North Africa's Sahara Desert to find out how wind turbines and solar farms might alter the desert's climate.
The team ran its model several times.In one run, it assumed that people would set up wind farms only.Another run assumed people would install just solar farms.A third assumed people would build both.They would affect the desert's weather with temperature and average daily rain increased — but differently.Installing a mix of solar farms and wind turbines brought about a bigger change — not in temperature but in rainfall.In the Sahara, having both wind and solar farms more than doubled the amount of rain that fell, up to 215.4 millimeters per day.
The models predicted that the average rainfall would increase over time, as more plants grew.Plants move water from the ground to the air.Warmer air can carry more water.So as this air rises, it can ferry more water up to become clouds.Those clouds can release rain, relieving the thirst of plants below.Over time, this process repeats itself over and over.This positive feedback can greatly boost rains.
Such rainfall changes could lead to better agriculture, says Safa.“More rain also would help wild plants grow.We believe that the countries in the Sahara should seriously consider investing in wind and solar power，” he added.
语篇解读：本文是一篇说明文。文章介绍了一项新的研究发现，可再生能源的使用能够增加沙漠地区的降雨量，有助于植物的生长。
1．What is the new finding of the research?
A．Deserts will be suitable for farming.
B．It costs much to get deserts greener.
C．Renewable energy can green a desert.
D．Clean energy helps plants grow better.
解析：选C 细节理解题。根据第一段中的A new study finds that such renewable energy might be green in another sense.Large collections of those turbines or solar panels appear capable of bringing rains to the desert and would allow more plants to grow.可知，研究发现这种可再生能源似乎能够给沙漠带来雨水，并能让更多的植物生长。换句话说，这些可再生能源可以绿化沙漠。故选C。
2．What discouraged experts from building energy farms?
A．High construction expenses.
B．A lack of suitable test sites.
C．Shortage of manpower.
D．Terrible climate.
解析：选A 细节理解题。根据第二段中的Building large wind or solar farms just to study their question was not an option.It would be too costly.可知，建造能源农场不是一个好的选择，因为太贵了。由此可推断出，阻止专家们建造能源农场的是高昂的建筑费用。故选A。
3．What was the advantage of the third run?
A．Saving more energy with less cost.
B．Doubling global rainfall per year.
C．Raising daily rainfall in the desert.
D．Decreasing temperature in the desert.
解析：选C 细节理解题。根据第三段中的A third assumed people would build both.和Installing a mix of solar farms and wind turbines brought about a bigger change — not in temperature but in rainfall.In the Sahara, having both wind and solar farms more than doubled the amount of rain that fell, up to 215.4 millimeters per day.可知，在第三次实验中，既建造了风力发电厂，又建造了太阳能发电厂，这种情况下，降雨量增加了一倍多，达到每天215.4毫米。由此可推断出，第三次实验的优势是增加了沙漠的日降雨量。故选C。
4．What may Safa advise the countries in the Sahara to do?
A．Build more farms to grow crops.
B．Save more water for agriculture.
C．Invest in wind and solar power.
D．Consider moving to other places.
解析：选C 推理判断题。根据最后一段Safa说的话可知，Safa建议撒哈拉沙漠地区的国家应认真考虑投资风能和太阳能，因为这有助于野生植物的生长，对环境是有好处的。故选C。
