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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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【简答题】汽包锅炉给水控制对象的特点是有迟延、有惯性、( )。
【单选题】所谓彩色木刻画就是用木刻套印的方法印成画模,人物、花鸟、山水……差不多跟中国 画画家笔下的真迹一模一样。我家里挂着一幅新罗山人的花鸟画,一块石头前伸出一枝海棠, 三个红胸鸟停在枝上,上下照应,瞧那神色正在那里使劲地叫呢!文中加点词运用不恰当的 是( )
A.
所谓
B.
差不多
C.
照应
D.
神色
【单选题】C 语言中,可将一系列语句置于一对( )之间从而构成复合语句。
A.
尖括号 ""
B.
圆括号 "( )"
C.
花括号 "{}"
D.
方框号 "[ ]"
【单选题】销售增长和相对市场占有率都高的是( )
A.
明星产品
B.
金牛产品
C.
问题产品
D.
瘦狗产品
【多选题】影响采用开环伺服系统的数控机床定位精度的主要因素是()。
A.
插补误差
B.
传动链的误差
C.
检测元件的检测精度
D.
机床热变型
E.
步进电机的性能
【多选题】影响采用开环伺服系统的数控机床定位精度的主要因素是
A.
插补误差
B.
传动链的误差
C.
检测元件的检测精度
D.
机床热变形
E.
步进电机的性能
【单选题】屈原是楚国王族后裔,楚国的姓是“芈”,“屈”为屈原的氏,其来源是?
A.
以封国、封邑为氏
B.
以居住地为氏
C.
以技艺、官职为氏
D.
以祖先名、字、谥号为氏
E.
以事或物为氏
【多选题】影响采用开环伺服系统的数控机床的特点是( )。
A.
定位精度低
B.
不容易调试
C.
主要用于小型数控机床
D.
价格低
E.
一般采用步进电机
【单选题】所谓彩色木刻画就是用木刻套印的方法印成画幅,人物、花鸟、山水……差不多跟中国画画家笔下的真迹一模一样。我家里挂着一幅新罗山人的花鸟画,一块石头前伸出一枝海棠,三个红胸鸟停在枝上,上下照应,瞧那神色,像是正在那里使劲地叫呢! 文中下划线字运用不恰当的是( )。
A.
所谓
B.
差不多
C.
照应
D.
神色
【单选题】所谓彩色木刻画就是用木刻套印的方法印成画幅,人物、花鸟、山水……差不多跟中国画画家笔下的真迹一模一样。我家里挂着一幅新罗山人的花鸟画。一块石头前伸出一枝海棠,三个红胸鸟停在枝上,上下照应,瞧那神色,像是正在那里使劲地叫呢!文中加下划线字,运用不恰当的是( )。
A.
所谓
B.
差不多
C.
照应
D.
神色
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