Sometimes, artists paint ______ for their own enjoyment or self-expression, choosing their
A. primarily
B. occasionally
C. reluctantly
D. generously
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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 Alois 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 researchers 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 important development, but cautioned that other promising tests for Alzheimer's have been disappointing.
The newly developed skin tests may be used in the future 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 consequences of Alzheimer's disease
Crystal Ear
One day a friend asked my wife Jill if I wanted a heating aid. "He certainly does. "replied Jill. After heating about a remarkable new product. Jill finally got up the nerve to ask me if I'd ever thought about getting a heating aid. "No way," I said. "It would make me look 20 years older." "No, no," she replied. "This is entirely different. It's Crystal Ear!"
Jill was right. Crystal Ear is different--not the old-styled body worn or over-the-ear aid, but all advanced personal sound system so small that it's like contacts(隐形眼镜) for your ears. And Crystal Ear is super-sensitive and powerful, too. You will hear sounds your ears have been missing for years. Crystal Ear will make speech louder, and the sound is pure and natural.
I couldn't believe how tiny it is. It is smaller than the tip of my little finger and it's almost invisible when worn. There are no wires, no behind-the-ear device. Put it in your ear and its ready-to-wear mold(形状) fits comfortably. Since it's not too loud or too tight, you may even forget that you're wearing it! Use it at work or at play. And if your hearing problem is worse in certain situations, use Crystal Ear only when you need it.
Heating loss, which occurs typically prior to teenage years, progresses throughout one's lifetime. Although hearing loss is now the world's number one health problem, nearly 90 percent of people suffering heating loss choose to leave the problem untreated. For many millions, treating hearing loss in a conventional way can involve numerous office visits, expensive testing and adjustments to fit your ear. Thanks to Crystal Ear, the "sound solution" is now convenient. Almost 90 percent of people with mild hearing loss, and millions more with just a little hearing drop-off (下降), can be dramatically helped with Crystal Ear. Moreover, its superior design is energy-efficient, so batteries can last months. Crystal Ear is now available to help these people treat their heating loss with a small hearing amplifier (放大器).
Initially the writer did not want to buy a hearing aid because ______.
A. it would make him look old
B. it would make him nervous
C. it was too expensive
D. it was old-styled
The Gene Industry
Major companies and already in pursuit of commercial applications of the new biology. They dream of placing enzymes in the automobile to monitor exhaust and send data on pollution to a microprocessor that will then adjust the engine. They speak of what the New York Times calls "metal-hungry microbes that might be used to mine valuable trace metals from ocean water". They have already demanded and won the right to patent new life forms.
Nervous critics, including many scientists, worry that there is corporate, national, international, and inter-scientific rivalry in the entire biotechnological field. They create images not of oil spills, but of "microbe spills" that could spread disease and destroy entire populations. The creation and accidental release of extremely poisonous microbes, however, is only one cause for alarm. Completely rational and respectable scientists are talking about possibilities that stagger the imagination.
Should we breed people with cow-like stomachs so they can digest grass and hay, thereby relieving the food problem by modifying us to eat lower down on the food chain? Should we biologically alter workers to fit the job requirement, for example, creating pilots with faster reaction times or assembly-line workers designed to do our monotonous work for us? Should we attempt to eliminate "inferior" people and breed a" super-race"? (Hitler tried this, but without the genetic weaponry that may soon issue from our laboratories.) Should we produce soldiers to do our fighting? Should we use genetic forecasting to pre-eliminate "unfit" babies? Should we grow reserve organs for ourselves, each of us having, as it were, a "savings bank" full of spare kidney, livers or hands?
Wild as these notions may sound, every one has its advocates (and opposers) in the scientific community as well as its striking commercial application. As two critics of genetic engineering, Jeremy Rifkin and Ted Howard, state in their book Who Should Play God? "Broad Scale genetic engineering will probably be introduced to America much the same way as assembly lines, automobiles, vaccines, computers and all the other technologies. As each new genetic advance becomes commercially practical, a new consumer need will be exploited and a market for the new technology will be created."
According to the passage, the exhaust from a car engine could probably be checked by______.
A. using metal-hungry microbes
B. making use of enzymes
C. adjusting the engine
D. patenting new life forms
By saying that "They held their ranks together"(Para. 2), the author means that the Republicans______.
A. kept indifferent to the declining support
B. were united to fight against public criticism
C. reorganized the army in Iraq
D. kept their position as the party in power