题目内容
"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？
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听力原文：There are countries that are stable and have no conflicts. But we all know that if there is conflict in one country, and that conflict overspills to another country, so it's an achievement that we have set in place an original mechanism to. deal with this.
An original mechanism to deal with conflicts is established in order to prevent overspilling of conflicts from one country into another country.
What is the best rifle for this passage？
Zoos are under a lot of pressure these days to justify their existence. In the past, collections of animals were assembled largely to entertain the public or to satisfy a private desire. There was often little understanding of the animal's biological or behavioral needs, and even less perception of a responsibility to justify the collection in terms of science, conservation or popular education. For responsible zoos, this has changed dramatically.
By acting as a reservoir for species, zoos can act as a safety device in case the species become extinct in nature. Zoos can also provide the animals necessary to reintroduce species extinct in the wild once the threats to their survival have been controlled. A second important function of any good zoo must be the education of the visitor. Regardless of the scientific expertise (专长) of the individual, he or she can expect to learn something every time he walks through the zoo gate.
For many people, especially those living in towns, this is the closest they will come to see wild animals. Even with the high quality of the current wildlife films, there is no replacement for seeing the real thing. One must appreciate that for many people an animal simply isn't real if they only see it on a television screen. Zoos provide an opportunity to make the emotional and rational commitment essential to the future of conservation.
Finally, it should be appreciated that zoos provide a unique opportunity for research, the results of which may be crucial to the survival of species.
Apart from the debate over whether zoos perform. a valuable role in society, they are often attacked on animal welfare grounds -- that they are little more than prisons, exploiting their inhabitants for commercial purposes. Unfortunately there is a tendency to tar (玷污) all zoos with the same brush, regardless of fundamental differences in their philosophy, the quality of care given to their animals, and their contribution to science and conservation.
Nobody is arguing that zoos are perfect or that they are a substitute for the wild. But it is important to place them -- the responsible, good zoos -- in the overall context of conservation, and to recognize that they and the staff they support have a valuable role to play in the future.
What is the author's argument in the passage？
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