皮皮学,免费搜题
登录
搜题
【单选题】
'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 has 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.
拍照语音搜题,微信中搜索"皮皮学"使用
参考答案:
参考解析:
知识点:
.
..
皮皮学刷刷变学霸
举一反三
【单选题】利用1K×4位的SRAM芯片,设计一个存储容量为4K×16位的SRAM存储器。
A.
4
B.
8
C.
16
D.
32
【单选题】采集到的病料,如果不能及时送检,如何保存?
A.
2-8℃冷藏保存
B.
常温保存
C.
-20℃保存
【单选题】采集到的细菌病料,如果不能及时送检,如何保存?
A.
2-8℃冷藏保存
B.
常温保存
C.
-20℃保存
【判断题】德国是世界上第一个建立医疗保险的国家,是现代社会保障的发源地。
A.
正确
B.
错误
【单选题】要得到函数 的图象,只要将函数 的图象
A.
向右平移 个单位
B.
向右平移 个单位
C.
向左平移 个单位
D.
向左平移 个单位
【单选题】(单选)用1K×4位的DRAM设计4K×16位的存储系统需要的芯片数是( )片。
A.
32
B.
4
C.
8
D.
16
【单选题】利用1K×4位的SRAM芯片,设计一个存储容量为1K×8位的SRAM存储器。
A.
2
B.
1
C.
4
D.
8
【单选题】用1K×4位的DRAM设计4K×8位的存储器的系统需要的芯片数是:()
A.
8
B.
16
C.
4
D.
32
【单选题】世界上第一个建立医疗保险制度的国家是(    )
A.
美国    
B.
德国
C.
日本    
D.
加拿大
E.
法国
【判断题】德国是世界上第一个建立医疗保险的国家,是现代社会保障的发源地。
A.
正确
B.
错误
相关题目: