第2部分：阅读判断 A Dolphin and an Astronomer
One day in 1963, a dolphin named Elvar and a famous astronomer, Carl Sagan, were playing a little game. The astronomer was visiting an institute which was looking into the way dolphins communicate with each other. Sagan was standing on the edge of one of the tanks where several of these friendly, highly intelligent creatures were kept. Elvar had just swum up alongside him and had turned on his back.
The dolphin wanted Sagan to scratch his stomach again, as the astronomer had done twice before. Elvar looked up at Sagan, waiting. Then, after a minute or so, the dolphin leapt up through the water and made a sound just like the word "more". The astonished astronomer went to the director of the institute and told him about the incident. 'Oh, yes. That's one of the words he knows,' the director said, showing no surprise at all.
Dolphins have bigger brain in proportion to their body size than humans have, and it has been known for a long time that they can make a number of sounds. What is more, these sounds seem to have different functions, such as warning each other of danger. Sound travels much faster and much further in water than it does in air. That is why the parts of the brain that deal with sound are much better developed in dolphin than in humans. But can it be said that dolphins have a 'language', in the real sense of the word? Scientists don't agree on this.
A language is not just a collection of sounds, or even words. A language has a structure and what we call a grammar. The structure and grammar of a language help to give it meaning. For example, the two questions "Who loves Mary?" and "Who does Mary love?" mean very different things. If you stop to think about it, you will see that this difference doesn't come from the words in the question but from the difference in structure. That is why the question "Can dolphins speak?" can't be answered until we find out if dolphins not only make sounds but also arrange them in a grammatical order which affects their meaning. 第一篇 "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 100 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 salt 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. 
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