C
A new study in West Africa shows how farm irrigationsystems powered by the sun can pro-duce more food and money for villagers． The study-in Benin found that solar - powered pumpsare effective in 8upplying water, especially during the long dry season．
Sub - Saharan Africa is the part of the world with the least food security． The United Na-tions Food and Agriculture Organization estimates that more"than one biillion of the world' s peo-ple faced hunger last year．Around 265 million of them live'south of the Sahara Desert:  Lack of  rainfallis one oftheir main causes offood shortages．．
Jennifer Bumey from Stanford University in Califomia led the study．The research team helped build three solar - powered drip irrigation -（滴灌） ,systems in northem Benin． Between 30 and 35 women used each system to pump water from the ground or a stream．Each woman was responsible for farming her own 120 sqrurre meters of land． They also farmed other land  collectively．
The solar - powered irrigation systems produced an average of nearly two tons of vegetables per montb． During the first year, the women．kept a monthly average of almost rune kilograms of vegetables for home use．They sold the surplus produce at local markets． The eamings greatly increased their ability to buy food during the dry season which can last six to nine months． Peo- ple in the'two villages with the systems were able to eat three to five more servingsof yegetables 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 croplamd 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．
66．Food security in Sub - Saharan Africa is insufficient mainly because of
A．lack of rainfall         B．limitation of farmland
C． a small crop variety   D．little sunlight
67．From the third paragraph we know that _______．
A．water is wasted by using the system
B． the farmers imgate the land together
C． all farmers use irrigation systems in northem Benin
D． the solar - powered systems take up more manpower
68．The underlined word "surplus" in the 4th paragraph most probably means_______
A．special             B．unnecessary      C．extra      D．abandoned
69．Usinf．solar power to pump water has advantages EXCEPT that
A．solar energy has higher cost at first
B．solar power helps to protect environment
C．solar power helps farmers increase eanungs
D． solar energy can be more economical in the long run
70．What can be the best title for the text?
A．Manpower affects rainfallin Africa
B．Irrigation by carrying water in buckets
C．Solar - powered pumps aid African farmers
D．Vegetable supply increased in African villages