第二部分阅读理解（共25小题。第一节每小题2分，第二节每小题1分；满分45分）
第一节 阅读下列短文，从每题所给的四个选项（A、B、C、D）中，选出最佳选项，并在答题卡上将该项涂黑。
A new study in West Africa shows how farm irrigation systems powered by the sun can produce more food and money for villagers. The study in Benin found that solar-powered pumps are effective in supplying water, especially during the long dry season.
Sub-Saharan Africa is the part of the world with the least food security. The United Nations Food and Agriculture Organization estimates that more than one billion of the world’s people faced hunger last year. Around two hundred sixty-five million of them live south of the Sahara Desert. Lack of rainfall is one of their main causes of food shortages.
Jennifer Burney from Stanford University in California led the study. The research team helped build three solar-powered irrigation systems in northern Benin.
The solar-powered irrigation systems produced an average of nearly two metric tons of vegetables per month.
They sold the surplus(过剩的) produce at local markets. The earnings greatly increased their ability to buy food during the dry season which can last six to nine months.
People in the two villages with the systems were able to eat three to five more serving of vegetables per day. But making the surplus available at markets also had a wider effect.
The study compared the villages with two others where women farmed with traditional methods like carrying water in buckets. The amount of vegetables eaten in those villages also increased, though not as much.
The researchers note that only four percent of the cropland in sub-Saharan Africa is irrigated. Using solar power to pump water has higher costs at first. But the study says it can be more economical in the long term than using fuels like gasoline, diesel or kerosene. And solar power is environmentally friendly.
1. People living in sub-Saharan Africa are short of food mainly because______.
A. it seldom rains there throughout the year   B. there is little farmland in the area
C. people there lack experience in farming    D. people know nothing about irrigation techniques
2. Which of the following is an advantage of Jennifer’s irrigation systems?
A. They are not affected by the weather.
B. They cost much less than traditional irrigation systems.
C. They have no bad effects on the environment.
D. They use less fuel than traditional irrigation systems.
3. We can learn from the last paragraph that______.
A. people in South Africa will soon be provided with enough food
B. the demand for fuels like gasoline will greatly decrease in Africa
C. people in sub-Saharan Africa don’t take agriculture seriously
D. it’s worthwhile to use the new irrigation systems on the while
4. People in the two villages owe all the following to Jennifer’s irrigation systems EXCEPT that ______.
A. they could buy more food during the dry season
B. they could eat more vegetables than usual every day
C. they could supply local markets with vegetables
D. they could provide people in other villages with food