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Studies show that in dreams things are seen and heard rather than thought. In terms of the senses, visual experience is present in almost all dreams; auditory experience in 40 to 50 percent; and touch, taste, smell, and pain in a relatively small percentage. A considerable amount of emotion is commonly present, usually a pure and single emotion such as fear, anger, or joy.
Two clearly distinguishable states of sleep exist. The first state, called NREM-sleep (non-rapid- eye-movement sleep), occupies most of the sleep period and is associated with a relatively low pulse and blood pressure, and few or no reports of dreaming. The second type of sleep, known as REM-sleep(rapid-eye-movement sleep)occurs cyclically during the sleep period with rapid eye movements and frequent dream reports. Typically, a person has four or five periods of REM-sleep during the night, whether the dreams are remembered often, rarely, or not本.文,来.源,于.贵,州.学,习.网,www.gzu521.com at all; they occur at intervals of about 90 minutes and altogether make up about 25 percent of the night’s sleep(as much as 50 percent in a newborn child). Evidence indicates that a dream period usually lasts from 5 to 20 minutes. Sounds and touches working on a dreamer can go into a dream if they occur during a REM-period. Although mental activity may be reported during NREM-sleep, these are usually short pieces of thought like experiences.
Modern dream research has focused on two general interpretations of dream content. In one view, dreams have no meaning of their own but are simply a process by which the brain integrates new information into memories. In the other view, dreams contain real meaning symbolized in a picture language distinct from conscious logical though. If dreams express important wishes, fears, concerns, and worries of the dreamer, the study and analysis of dreams can help reveal previously unknown aspects of a person’s mental functioning.
1. There are in general two opinions about what we experience in a dream:
A. one, we “see” our dreams, and two, we “think” our dreams.
B. one, we are happy, and two, we are angry.
C. one, dreams put new information into our memories, and two, dreams have real meanings in pictures different from our logical thinking.
D. we have pictures in dreams because one, we have slow eye movements, and two, we have rapid eye movements.
2. According to this article, we
A. often think seriously when we are dreaming.
B. hardly ever hear music when we are dreaming.
C. very often feel something tastes good when we are dreaming.
D. almost always see different “pictures” when we are dreaming.
3. In your dreams, you
A. very often feel happy and unhappy at the same time.
B. always feel that you are afraid of somebody.
C. seldom feel fear now and joy later.
D. only feel anger.
4. This essay tells us that
A. people usually dream in a NREM sleep.
B. people usually dream in an REM sleep.
C. people always remember what they have dreamed in an REM sleep.
D. people may have an REM sleep all night through.
5. Based on what is discussed in this writing, an adult may have at most about _______ of the time of his or her sleep dreaming.
A. 90% B. 50% C. 25% D. 20%
Most of the food we eat is turned into glucose for our bodies to use for energy. The pancreas, an organ near the stomach, makes a hormone called insulin to help glucose get into your body cells. When you have diabetes, your body either doesn’t make enough insulin or can’t use its own insulin well. This problem causes glucose to build up in your blood.
You may recall having some of these signs before you found out you had diabetes：
*Being very thirsty.
*Urinating a lot—often at night.
*Having unclear vision from time to time.
*Feeling very tired much of the time.
*Losing weight without trying.
*Having very dry skin.
*Having sores that are slow to heal.
*Getting more infections than usual.
Two main types of diabetes are Type 1 and Type 2. Another type of diabetes appears during pregnancy in some women. It’s called gestational diabetes.
One out of ten people with diabetes has Type 1 diabetes. These [ 本_资_料_来_源_于_贵_州_学_习_网 ｇｚｕ５２１.ｃｏｍ ) people usually find out they have diabetes when they are children or young adults. The pancreas of a person with Type 1 makes little or no insulin. People with Type 1 diabetes must inject insulin every day to live.
Most people with diabetes have Type 2 diabetes. The pancreas of people with such diabetes keeps making insulin for some time, but the body can’t use it well. Most people with Type 2 find out about their diabetes after age 30 or 40.
Some risk factors which make people more likely to get Type 2 diabetes are：
*A family history of diabetes.
*Lack of exercise.
*Weighing too much.
Diabetes can hurt your eyes, your kidneys, and your nerves. It can lead to problems with the blood circulation in your body. Even your teeth and gums can be harmed. And diabetes in pregnancy can cause special problems.
1. This writing is meant to tell people
A. how to avoid getting diabetes.
B. what to pay attention to when they have diabetes.
C. what diabetes is.
D. about the latest development in curing diabetes.
2. A person with diabetes may have had all the following signs EXCEPT
A. becoming fatter and fatter.
B. becoming thinner and thinner.
C. having to get out of bed at night and urinate.
D. feeling like drinking a lot of water very often.
3. Which of the following statements is TRUE?
A. Most persons with Type 1 or Type 2 diabetes are women in pregnancy.
B. Most women in pregnancy may have the danger of getting diabetes.
C. We find more persons with Type 2 diabetes among children than adults.
D. We find more persons with Type 2 diabetes among adults than children.
4. When you have Type 2 diabetes, it is sometimes possible to find that
A. your teenage son has diabetes too.
B. your father has diabetes too.
C. your father-in-law is too fat.
D. your brother does not like sports.
5. People get diabetes because
A. their stomachs are not able to produce enough insulin.
B. their pancreas are not able to produce enough glucose.
C. there is too much glucose in their blood.
D. there is too much insulin in their blood.
High Stress May Damage Memory
According to a report issued in May 1998, elderly people who have consistently high blood levels of cortisol don’t score as well on memory tests as their peers with lower levels of the stress hormone. What’s more, high levels of cortisol are also associated with shrinking of the hippocampus, a region of the brain that plays a key role in learning and memory.
The findings suggest that even cortisol levels in the normal, “healthy “range can actually accelerate brain aging.
The study results “now provide substantial evidence that long-term exposure to adrenal stress hormones may promote hippocampal aging in normal elderly humans, “write Nada Porter and Philip Landfield of the University of Kentucky in Lexington in their editorial. Cortisol is a hormone released in response to stress by the adrenal glands, which sit on top of the kidneys.
Over a 5 to 6-year period. Dr. Sonia Lupien and his colleagues measur资:料;来/源,于ＧＺＵ５２１学:习;网 http://Ｇzｕ５２1.COmed 24-hour cortisol levels in 51 healthy volunteers, most of whom were in their 70s.
Despite wide variation in cortisol levels, the participants could be divided into three subgroups: those whose cortisol progressively increased over time and was currently high (increasing/high); those whose cortisol progressively increased over time and was currently moderate (increasing/moderate); and subjects whose cortisol decreased, but was currently moderate (decreasing/moderate).
The researchers tested the volunteers’ memory on six people in the increasing/high category and five people in the decreasing/moderate group. The groups did not differ on tests of immediate memory, but the increasing/high cortisol group had other memory problems compared with those in the decreasing/moderate group.
The researchers also found that the total volume of the hippocampus in those in the increasing/high group was 14% lower than those in the decreasing/moderate group, although there were no differences in other brain regions.
The results suggest that “. . . brain aging can be accelerated by levels of adrenal hormones that are not generally regarded as pathological and that variation within this normal range is related to variation in the rate of brain aging,” write Porter and Landfield. “This further suggests that chronic stress may accelerate the worsening of hippocampus.”
1. The part of the brain important for a person’s learning and memory is
A. the cortisol. B. the adrenal glands.
C. the stress hormones. D. the hippocampus.
2. When the levels of cortisol go higher, the hippocampus in the brain may
A. become larger. B. become smaller.
C. be missing. D. be totally damaged.
3. According to the article, when people feel too worried or nervous or when they overwork,
A. the adrenal glands will produce a stress hormone.
B. the kidneys will produce adrenal glands.
C. the hippocampus will produce high levels of cortisol in the blood.
D. the cortisol will produce something that makes a poorer memory.
4. When the total volume of the hippocampus becomes smaller, other brain regions
A. become smaller too. B. become larger.
C. may remain the same in size. D. may be damaged.
5. Porter and Landfield’s research shows that
A. the change in the levels of adrenal hormones has nothing to do with the degree of brain aging.
B. the change in the levels of adrenal hormones has a lot to do with the degree of brain aging.
C. the long-term stress will gradually make the hippocampus worse.
D. None of the above is correct.
FDA: Human, Animal Waste Threatens Produce
The biggest food safety risk for fresh fruits and vegetables as they are grown, picked or processed comes from human and animal waste, the U. S. Food and Drug Administration (FDA). said Friday.
More than 9, 000 Americans die each year from food-borne diseases and some scientists believe fresh produce is the biggest carrier of contamination.
The FDA issued a set of draft guidelines for U. S. and foreign growers to carefully monitor worker hygiene, water quality, manure management and transportation.
These 34-page draft guidelines urged growers to give workers lessons on basic hygiene such as using soap to wash their hands, covering wounds that could come into contact with produce, and using only clean toilets.
The FDA guidelines identified “the major source of contamination “for fresh produce as human or animal feces.
“We think just proper controls and proper attention to detail would 本_文_来_源_于_我_的_学_习_网Www.GZU521.Commake a big difference in food safety,” said and FDA official, “It is our belief that these guidelines would not be very costly.”
But grower groups disagreed with the FDA’s assessment. “Most food-borne disease outbreaks that happen further down the distribution line are due to contamination because people preparing food are not properly washing their hands, “said Stacey Zawal, an official with United Fresh Fruit and Vegetable Association. “That is not necessarily true for growers and packers.”
Some U. S. grower organizations have expressed concern that the agency is interfering with on-farm practices. Others object to the FDA’s proposal to have growers formally document the picking, handling and transportation of produce so that health officials could quickly recall foods if necessary.
Consumer groups criticized the FDA guidelines as of little use because they will not carry the force of law. But stricter regulations could evolve as researchers find new technology or methods to kill harmful bacteria or parasites, the FDA said.
The FDA recommendations are due to be made final by the FDA later this year for use by U.S. and foreign growers. The matter of encouraging foreign growers to adopt the guidelines remains somewhat tricky but FDA officials say it is vital because of the huge amount of imported produce.
1. “Food-borne diseases” in this essay means those diseases
A. which people get by eating fruits which have been polluted
B. which people get by eating too many kinds of food.
C. which many kinds of fruit get when polluted by feces.
D. which fruit-growers get by their failure to keep themselves clean.
2. Some fruit grower groups believe that most food-borne diseases are caused by
A. growers’ lack of attention to personal hygiene.
B. lack of effective guidelines.
C. the FDA’s decision to import more foreign fruits and vegetables.
D. people involved in distributing fresh produce.
3. An FDA official said that putting the guidelines into practice
A. would be too costly to be effective.
B. would not cost any money.
C. would not be very expensive.
D. would needs lots of money.
4. Consumer groups criticized the FDA guidelines because they didn’t think that these guidelines
A. had won enough support from the farmers.
B. had been written with strict regulations.
C. would surely be carried out.
D. included new technology.
5. The last paragraph suggests that
A. some tricks need to be adopted to encourage foreign growers to follow the FDA guidelines.
B. a good way should be found to encourage foreign growers to follow the FDA guidelines.
C. foreign growers consider the guidelines to be of great importance to them.
D. it is almost impossible to ask foreign farmers to follow the guidelines.
More about Alzheimer’s Disease
Scientists have developed skin tests that may be used in the future to identify people with Alzheimer’s disease and may ultimately allow physicians to predict who is at risk of getting this neurological disorder.
The only current means of diagnosing the disease in a living patient is a long and expensive series of tests that eliminate every other cause of dementia.
“Since Aloes Alzheimer described the disease nearly a century ago, people have been trying to find a way to accurately diagnose it in its early stages,” said Patricia Grady, acting director of the National Institute of Neurological Disorders and Stroke in Bethesda, Maryland. “This discovery, if confirmed, could prove a big step forward in our efforts to deal with and understand the disease.”
Alzheimer’s is the single greatest cause of mental deterioration in older people, affecting between 2.5 million and 4 million people in the United States alone. The devastating disorder gradually destroys memory and the ability to function, and eventually causes death. There is currently no known treatment for the disease.
Researches discovered that the skin cells of Alzheimer’s patients have defects that interfere with their ability to regulate the flow of potassium in and out of the cells. The fact that the cell defects are present in the skin suggests that Alzheimer’s results from physiological changes throughout the body, and that dementia may be the first noticeable effect of these changes as the defects affect the cells in the brain, scientists said.
The flow of potassium is especially critical in cells responsible for memory formation. The scientists also found two other defects that affect the cells’ supply of calcium, another critical element.
One test developed by researches calls for growing skin cells in a laboratory culture and then testing them with an electrical detector to determine if the microscopic tunnels that govern the flow of potassium are open. Open potassium channels create a unique electrical signature.
A spokesman for the Alzheimer’s Association said that if the validity of the diagnostic test can be proven it would be an important development, but cautioned that other promising tests for Alzheimer’s have been disappointing.
1. The newly developed skin tests may be used in the future is to allow doctors to
A. cure those with Alzheimer’s disease.
B. discover the cause of Alzheimer’s disease.
C. predict who might get Alzheimer’s disease.
D. find the consequence of Alzheimer’s disease.
2. The passage indicates that Alzheimer’s is a disease
A. common to people, old and young.
B. not costly to be cured.
C. easy to be handled.
D. not easy to be diagnosed.
3. Which of the following statements about the Alzheimer’s disease is NOT true?
A. It was so named because Aloes Alzheimer first described it.
B. It is the greatest cause of mental deterioration in older people.
C. It can destroy memory gradually and eventually cause death.
D. There are many ways to deal with and cure the disease now.
4. Which of the following about the relationship between Alzheimer’s and dementia is true?
A. Dementia is one of the signs of Alzheimer’s
B. Alzheimer’s is one of the causes of dementia.
C. They are two completely different diseases.
D. They are similar defects of the human brain.
5. The last paragraph implies that the diagnostic test
A. will not be as promising as others.
B. is a very important development.
C. may not be proven valid smoothly.
D. will surely be disappointing in the end.
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