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Living with Computer Compared with the clear words of her boyfriend on screen, his accent is A．obscure. B．distinct. C．unreal. D．misleading.
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The Body Clock Why is it that flying to New York from London will leave you feeling less tired than flying to London from New York The answer may be a clear case of biology not being able to keep up with technology. Deep inside the brain there is a "clock" that governs every aspect of the body’s functioning: sleep and wake cycles, levels of alertness, performance, mood, hormone levels, digestion, body temperature and so on. It regulates all of these functions on a 24-hour basis and is called the biological clock. This body clock programmes us to be sleepy twice a day, between 3-5 am and again between 3-5 pm. Afternoon tea and nap are all cultural responses to our natural biological sleepiness in the afternoon. One of the major causes of the travellers’ malady known as jet lag is the non-alignment of a person’s internal body clock with clocks in the external world. Crossing different time zones confuses the biological clock, which then has to adjust to the new time and patterns of light and activity. To make matters more complex, not all internal body functions adjust at the same rate. So your sleep/wake may adjust to a new time zone at one rate, while your temperature adjusts at a different pace. Your digestion may be on a different schedule altogether. Though we live in a 24-hour day, the natural tendency of the body clock is to extend our day beyond 24 hours. It is contrary to our biological programming to "shrink" our day’. That is why traveling in a westward direction is more body-clock friendly than flying east. NASA studies of long haul pilots showed that westward travel was associated with significantly better sleep quantity and quality than eastward flights. When flying west, you are "extending" your day, thus traveling in the natural direction of your internal clock. Flying eastward will involve "shrinking" or reducing your day and is in direct opposition to your internal clock’s natural tendency. One of the more common complaints of travelers is that their sleep becomes disrupted. There are many reasons for this, changing time zones and schedules, changing light and activity levels, trying to sleep when your body clock is programmed to be awake, disruption of the internal biological clock and working longer hours. It is often suggested that you adjust your watch as soon as you board a plane, supposedly to try to help you adjust to your destination’s schedule as soon as you arrive. But it can take the body clock several days to several weeks to fully adjust to a new time zone. So, our body clock truly can "govern" us. The role of the body clock is to
"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 salt and store what they do absorb in cells but 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. Flowers and Yeo have started a programme
The Weight Experiment Nicola Waiters has been taking part in experiments in Scotland to discover why humans gain and lose weight. Being locked in a small room called a "calorimeter" (热量测量室) is one way to find out . 1．The signs above the two rooms read simply "Chamber One" and "Chamber Two". These are the calorimeters: 4m by 2m white-walled rooms where human volunteers are locked up in the name of science. Outside these rooms another sign reads "Please do not enter—work in progress" and in front of the rooms advanced machinery registers every move the volunteers make. Each day, meals measured to the last gram are passed through a hole in the wall of the calorimeter to the resident volunteer. 2．Nicola Waiters is one of twenty volunteers who, over the past eight months, have spent varying periods inside the calorimeter. Tall and slim, Nicola does not have a weight problem, but thought the strict diet might help with her training and fitness programme. A self-employed community dance worker, she was able to fit the experiment in around her work. She saw an advert for volunteers at her local gym and as she is interested in the whole area of diet and exercise, she thought she would help out. 3．The experiment on Nicola involved her spending one day on a fixed diet at home and the next in the room. This sequence was repeated four times over six weeks. She arrived at the calorimeter at 8:30 am on each of the four mornings and from then on everything she ate or drank was carefully measured. Her every move was noted too, her daily exercise routine timed to the last second. At regular intervals, after eating, she filled in forms about how hungry she felt and samples were taken for analysis. 4．The scientists help volunteers impose a kind of order on the long days they face in the room. "The first time, I only took one video and a book, but it was OK because I watched TV the rest of the time," says Nicola. And twice a day she used the exercise bike. She pedaled (踩踏板) for half an hour, watched by researchers to make sure she didn’t go too fast. 5．It seems that some foods encourage you to eat more, while others satisfy you quickly. Volunteers are already showing that high-fat diets are less likely to make you feel full. Believing that they may now know what encourages people to overeat, the researchers are about to start testing a high-protein weight-loss diet. Volunteers are required and Nicola has signed up for further sessions. A．What does the calorimeter look like inside B．What program was designed for the experiment C．What is a calorimeter D．What is the first impression E．How do the volunteers kill the time F．Why did Nicola join in the experiments Paragraph 1 ______
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 brains 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 dolphins 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. The dolphin leapt up into the air because Sagan was too near the water. A．Right B．Wrong C．Not mentioned
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