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'Salty' Rice Plant Boosts Harvests 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(红树林) 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 slat 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 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. 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.
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A.
肋骨骨折
B.
肋软骨炎
C.
白血病
D.
肋间神经炎
E.
胸骨骨折
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【单选题】下面关于成员函数重载运算符和友元函数重载运算符叙述正确的是( )。
A.
成员函数和友元函数可重载的运算符是不相同的
B.
成员函数和友元函数重载运算符时都需要用到 this 指针
C.
成员函数和友元函数重载运算符时都需要声明为公有的
D.
成员函数和友元函数重载运算符时的参数可能是相同的
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A.
用软件创作
B.
用扫描仪扫描
C.
用数码相机拍摄
D.
从屏幕、动画、视频中捕捉
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A.
基本正相关
B.
完全正相关
C.
完全无关
D.
基本无关
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A.
贯彻党的教育方针和实施素质教育的需要
B.
学生身心发展的需要
C.
学校实际
D.
体育与健康课程的特点和功能的需要
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A.
社会公德的主要内容有 A.文明礼貌
B.
助人为乐
C.
爱护公物、保护环境
D.
奉献社会
【单选题】当相关系数r等于+1时,表明成本与业务量之间的关系是
A.
完全正相关
B.
基本正相关
C.
完全无关
D.
基本无关
【单选题】胸骨压痛和叩击痛常见于( )
A.
气胸常
B.
胸腔积液
C.
肋间神经炎
D.
急性白血病
E.
气管内异物
【单选题】当相关系数r等于+1时,表明成本与业务量之间的关系是( )
A.
基本正相关
B.
基本无关
C.
完全正相关
D.
完全无关
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