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  3. British scientists are breeding a new generation of rice plants that will be able to grow in soil containing salt water. Their w

British scientists are breeding a new generation of rice plants that will be able to grow in soil containing salt water. Their w

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问题     British scientists are breeding a new generation of rice plants that will be able to grow in soil containing salt water. Their work may enable abandoned farms to become productive once more. Tim Flowers and Tony Yeo, from Sussex University’s School of Biological Sciences, have spent several years researching how crops, such as rice, could be made to grow in water that has become salty. The pair have recently begun a three-year programme, funded by the Biotechnology and Biological Sciences Research Council, to【C1】______which genes enable some plants to survive salty conditions. The aim is to breed this【C2】______into crops, starting with rice. It is estimated that each year more than 10m hectares of agricultural land are【C3】______because salt gets into the soil and stunts plants. The problem is caused by several factors. In the tropics, mangroves(红树林)that【C4】______swamps and traditionally formed【C5】______to sea water have been cut down. In the Mediterranean, a series of【C6】______have caused the water table to drop, allowing sea water to seep in. In Latin America, irrigation often causes problems when water is【C7】______by the heat, leaving salt deposits behind. Excess salt then enters the plants and prevents them functioning【C8】______. Heavy concentrations of minerals in the plants stop them drawing up the water they need to survive. To overcome these problems, Flowers and Yeo decided to breed rice plants that take in very little salt and store what they do absorb in cells that do not affect the plants’ growth. They have started to breed these characteristics into a new rice crop, but it will take about eight harvests before the resulting seeds are ready to be considered for【C9】______use. Once the characteristics for surviving salty soil are known, Flowers and Yeo will try to breed the【C10】______genes into all manners of crops and plants. Land that has been abandoned to nature will then be able to bloom again, providing much needed food in the poorer countries of the world.
A)evaporated I)create
B)barriers J)capability
C)normally K)establish
D)economic L)ensure
E)excluded M)capacity
F)lost N)commercial
G)droughts O)appropriate
H)perfectly
【C3】
选项
答案F
解析 空前系动词提示所填词可能为动词的分词形式或形容词。备选项中动词的分词都不能与agricultural land构成合理的动宾关系，故所填词只能为形容词。根据常识可知，salt侵入土壤，阻碍植物的生长会使agricultural land(农业用地)减少。备选项中的形容词用在句中符合句意要求的只有F)lost。如果不了解lost的形容词用法而将其归结到动词的过去分词的话，很难做对本题。
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