题目内容
（请给出正确答案）
The rats fed unrestricted diets do NOT
A．have one preventing-aging protein increased.
B．have their cell death increased or doubled.
C．have their DNA fragmentation doubled.
D．have the levels of proteins increased.
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The rats fed unrestricted diets do NOT ______
A．have one preventing-aging protein increased
B．have their cell death increased or doubled
C．have their DNA fragmentation doubled
D．have the levels of proteins increased
A．The rats " brain serotonin levels would not decrease.
B．The rats" brain tryptophan levels would decrease.
C．The rats" tyrosine levels would increase less quickly than would their leucine levels.
D．The rats would produce more insulin.
E．The rats would produce neurotransmitters other than serotonin.
【C1】
A．Meanwhile
B．Therefore
C．However
D．Moreover
【C1】
A．time
B．breakthrough
C．accomplishment
D．effort
Mind Your Calories or Your Waistline？
Cutting back the calories may do more than whittle your waistline; it could protect your brain from the effects of aging. A new study suggests that calorie restriction can help slow the normal process of cell death that happens with age.
Researchers say the body naturally goes through a process known as apoptosis, or cell death, to destroy old cells so new ones can be made, and many factors can alter this process. Age-related diseases, such as Alzheimer's and Parkinson's, cause a higher-than-normal loss of cells in the brain, which can lead to loss of function.
Previous studies have suggested that calorie restriction can boost life span and mental capacity. That prompted researchers to look at whether cutting calories might also play a role in protecting aging brain cells. They compared levels of proteins indicating brain cell death in two groups of rats. One group was given unrestricted access to food and water throughout their lives. The other was given 40% fewer calories (but still adequate nourishment) than the unrestricted group.
They found that the levels of these proteins increased with normal aging in the rats fed unrestricted diets. The rats given a restricted diet did not have an increase in the levels of these proteins.
Another protein thought to protect from cell death dropped by 60% in the well-fed rats, but it actually increased over time in the calorie-restricted rats.
Finally, DNA fragmentation, a third indicator of cell death, more than doubled in the unrestricted rats with age, but this increase was 36% less in the calorie-restricted rats.
Although the results are promising, researchers say more study is needed to completely understand the processes that lead to cell death and the role nutrition plays in that process.
Meanwhile, they say, their study provides yet another reason to watch what you eat. "We're not going to do it right away to improve our memories; we're going to do it probably in general for the first reasons, which would be to prevent cardiovascular disease and cancer," says Christian Leeuwenburgh at the University of Florida.
The main purpose of these researchers is ______
A．to help to destroy old cells and boost new ones
B．to alter the natural process known as apoptosis
C．to find out ways to protect aging brain cells
D．to compare different levels of proteins
By mating in successive generations only those animals that failed to develop hypertension from salt ingestion, a resistant strain (the" R" strain) has been evolved in which consumption of large quantities of salt fails to influence the blood pressure significantly. In contrast, by mating only animals that quickly develop hypertension from salt, a sensitive strain ("S" strain) has also been developed.
The availability of these two strains permits investigations not heretofore possible. They provide a plausible laboratory model on which to investigate some clinical aspects of the human proto - types of hypertension. More important, there might be the possibility of developing methods by which genetic susceptibility of human beings to high blood pressure can be defined without waiting for its appearance.
Which statement relates the main idea of this passage？
A．When salt is added to their diets, rats and men react in much the same way.
B．The near future will see a cure for high blood pressure.
C．Modem research has shown that high blood pressure is a result of salt in the diet.
D．A tendency toward high blood pressure may be a hereditary factor.
Section B
Directions: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You should decide on the best choice.
People with pets find it hard to believe, but scientists continue to debate whether or not animals are conscious—that is, whether they're aware of themselves as individuals.
Some still claim that anything animals do is strictly the result of conditioning. Others are willing to grant animals a certain amount of intelligence, but argue that animals are no more self-aware than computers, which, after all, are also capable of complex, seemingly conscious behavior.
One sign of intelligence, if not necessarily consciousness, is tool use. Chimpanzees use sticks to reach for things and fish for termites; they've even been seen to attach two sticks together to make a longer stick. Non-primates can be just as ingenious. One scientist had a crow living in his laboratory who was fed dry mash that had to be moistened before it could be eaten. Occasionally the keepers forgot to moisten it. The crow used a cup he had been given as a toy to get his own water and moisten the mash himself!
Egyptian vultures throw rocks at ostrich eggs to break them open; the woodpecker finch, of the Galapagos islands, uses a cactus spine to pry grubs out of tree branches; some green herons will drop small objects onto the surface of the water to lure fish to the surface.
Dolphins have no hands, but they've learned to carry rocks around by sucking them into their blowholes. Dolphins will also blow bubble rings, then play with them as they rise to the surface. Sometimes they'll drop bits of fish or seaweed into the center of a bobble ring just to see what happens.
Nevertheless, many scientists still think that animals are basically sleepwalkers, carrying out complex actions but completely unaware they are doing so.
This notion only dates back to the 1920s, when the psychological theory known as behaviorism took hold. Behaviorists said that any animal behavior, no matter how complex, could be explained in terms of the interaction of learned responses to stimuli. Behaviorism made it possible for psychologists to carry out rigorous experiments, and so it became very popular.
The problem with animal consciousness is that it's almost impossible to prove rigorously. Still, there is evidence: not only the common-sense evidence pet-owners provide, but experimental evidence (i.e., "if rats and humans react in exactly the same way to certain situations, and humans are aware of why they're acting that way, maybe rats are too") and indirect evidence (certain brain waves that seem to be linked to conscious thoughts in humans occur in animals, too).
Consciousness, argue the scientists who believe animals possess it, is too important to survival for animals not to possess it. When something unusual or unexpected happens, an organism needs to figure out how to escape or otherwise cope. That's when consciousness swings into action, and ally animal without it is at a terrible disadvantage.
What's the topic in this passage？
A．Animal consciousness.
B．Animal behavior.
C．Tool use by animals.
D．Signs of animal intelligence.
Controlling Robots with the Mind
Belle, our tiny monkey, was seated in her special chair inside a chamber at our Duke University lab. Her right hand grasped a joystick (操纵杆) as she watched a horizontal series of lights on a display panel. She knew that if a light suddenly shone and she moved the joystick left or right to correspond to its position, she would be sent a drop of fruit juice into her mouth.
Belle wore a cap glued to her head. Under it were four plastic connectors, which fed arrays of microwires-each wire finer than the finest sewing thread- into different regions of Belle's motor cortex (脑皮层), tile brain tissue that plans movements and sends instructions. Each of the 100 microwires lay beside a single motor neuron (神经元). When a neuron produced an electrical discharge, the adjacent microwire would capture the current and send it up through a small wiring bundle that ran from Belle's cap to a box of electronics on a table next to the booth. The box, in turn, was linked to two computers, one next door and the other half a country away.
After months of hard work, we were about to test the idea that we could reliably
translate the raw electrical activity in a living being's brain-Belle's mere thoughts-into signals that could direct the actions of a robot. We had assembled a multi-jointed robot arm in this room, away from Belle's view, which she would control for the first time. As soon as Belle's brain sensed a lit spot on the panel, electronics in the box running two real-time mathematical models would rapidly analyze the tiny action potentials produced by her brain cells. Our lab computer would convert the electrical patterns into instructions that would direct the robot arm. Six hundred miles north, in Cambridge, Mass, a different computer would produce the same actions in another robot arm built by Mandayam A. Srinivasan. If we had done everything correctly, the two robot arms would behave as Belle's arm did, at exactly the same time.
Finally the moment came. We randomly switched on lights in front of Belle, and she immediately moved her joystick back and forth to correspond to them. Our robot arm moved similarly to Belle's real arm. So did Sriniwlsan's. Belle and the robots moved in synchrony (同步), like dancers choreographed (设计舞蹈动作) by the electrical impulses sparking in Belle's mind.
In the two years since that day, our labs and several others have advanced neuroscience, computer science and microelectronics to create ways for rats, monkeys and eventually humans to control mechanical and electronic machines purely by "thinking through," or imagining, the motions. Our immediate goal is to help a person who has been unable to move by a neurological (神经的) disorder or spinal cord (脊髓) injury, but whose motor codex is spared, to operate a wheelchair or a robotic limb.
Belle would be fed some fruit juice if she
A．grasped the joystick.
B．moved the joystick to the side of the light.
C．sat quietly in a special chair.
D．watched lights on a display panel.
根据下列文章,请回答 41～45 题。 Controlling Robots with the Mind
Belle, our tiny monkey, was seated in her special chair inside A cha mber at our Duke University lab. Her right hand grasped a joystick (操纵杆) as she watched A horizontal series of lights on adisplay panel. She knew that if alight suddenly sho, ne and she moved the joystick left or right to correspond to its position, she would be sent adrop of fruit juice into her mouth.
Belle wore A cap glued to her head. Under it were four plastic connectors, which fed arrays of microwires - each wire finer than the finest sewing thread- into different regions of Belle's motor cortex, the brain tissue that plans movements and sends instructions. Each of the 100 microwires lay beside A single motor neuron (神经元) When aneuron produced an electrical discharge, the adjacent microwire would capture the current and send it up through asmall wiring bundle that ran from Belle's cap to A box of electronics on A table next to the booth. The box, in turn, was linked to two computers, one next door and the other half acountry a way.
After months of hard work, we were about to test the ide athat we could reliably translate the ra w electrical activity in aliving being's brain - Belle's mere thoughts - into signals that could direct the actions of arobot. We had assembled a multi jointed robot arm in this room, a way from Belle's view, which she would control for the first time. As soon as Belle's brain sensed alit spot on the panel, electronics in the box running two real-time mathematical models would rapidly analyze the tiny action potentials produced by her brain cells. Our lab computer would convert the electrical patterns into instructions that would direct the robot arm。 Six hundred miles north, in Ca mbridge, Mass, adifferent computer would produce the sa me actions in another robot arm built by Mandaya m A． Srinivasan, If we had done everything correctly, the two robot arms would beha ve as Belle's arm did, at exactly the sa me time.
Finally the moment ca me. We randomly switched on lights in front of Belle, and she immediately moved her joystick back and forth to correspond to them. Our robot arm moved similarly to Belle's real arm. So did Srinivasan's. Belle and the robots moved in synchrony (同步), like dancers choreographed (设计舞蹈动作) by the electrical impulses sparking in Belle's mind.
In the two years since that day, our labs and several others ha ve advanced neuroscience, computer science and microelectronics to create ways for rats, monkeys and eventually humans to control mechanical and electronic machines purely by"thinking through," or ima gining, the motions. Our immediate goal is to help A person who has been unable to move by A neurological (神经的) disorder or spinal cord (脊髓) injury,but whose motor cortex is spared, to operate A wheelchair or A robotic limb.
第11题：Belle would be fed some fruit juice if she
A．grasped the joystick.
B．moved the joystick to the side of the light.
C．sat quietly in A special chair.
D．watched lights on A display panel.
In one single year, rats eat to times______weight.
A．its
B．their
C．ones
D．of
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