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 establish which genes enable some plants to survive salty conditions. The aim is to breed this capability into crops, starting with rice. It is estimated that each year more than 10m hectares (公顷) of agricultural land are lost because salt gets into the soil and stunts (妨碍生长) plants. The problem is caused by several factors. In the tropics, mangroves (绿树林) that create swamps (沼泽) and traditionally formed barriers to sea water have been cut down. In the Mediterranean, a series of droughts have caused the water table to drop, allowing sea water to seep (渗透) in. In Latin America, irrigation often causes problems when water is evaporated (蒸发) by the heat, leaving salt deposits behind. Excess salt then enters the plants and prevents them functioning normally. 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 but 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 commercial use. Once the characteristics for surviving salty soil are known, Flowers and Yeo will try to breed the appropriate 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.
单选题
Which of the following statements about Flowers and Yeo is true? A.They are students at Sussex University. B.They are rice breeders. C.They are husband and wife. D.They are colleagues at an institution of higher learning.
【正确答案】
D
【答案解析】第二段的第一句话把两位研究人员Tim Flowers和Tony Yeo的是系讲得很清楚,他们来自同一所大学Sussex University的School of Biological Sciences,故是同事。从上下文看他们不可能是学生,更不会是种水稻的;第三段的第一句里用了pair这个词,但pair不一定就是夫妻,从他们的名字看他们不同姓,而且他们的名字Tire和Tony都是男性的名字。
单选题
Flowers and Yeo have started a programme A.to find ways to prevent water pollution. B.to identify genes that promote growth in salty soil. C.to breed rice plants that taste salty. D.to find ways to remove excessive salt from soil.
【正确答案】
B
【答案解析】本题的答案可以在第三段里找到,这段的第一句话说他们开始了一个为期三年的研究项目,目的是establish which genes enable some plants to surrive salty condition(确认啊些基因使得某些作物能在含盐的条件下生长)。这和选项B:to identify genes that promote growth in salty soil是同一个意思。
单选题
Which of the following is NOT mentioned as a cause of the problem discussed in the passage? A.Natural barriers to sea water have been destroyed. B.The water table has gone down after droughts. C.Sea level has been continuously rising. D.Evaporation of water leaves salt behind.