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HOW should cyclists prepare for the worst？
A．They should always carry enough money in case of difficulty.
B．They should carry a spare set of batteries for bicycle lamps.
C．They should never ride on their own.
D．They should keep a puncture repair kit and a basic tool kit at hand.
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A、capturing
B、captured
C、was captured
D、to be captured
A．Synchronic
B．Chronological
C．Diachronic
D．Linear
A．the students
B．class preparation
C．class atmosphere
D．class interaction
A growing body of research suggests that chronic illness is not an inevitable consequence of aging, but more often the result of lifestyle. choices. "People used to say, 'who would want to be 100？'" says Dr. Thomas Perls, an instructor at Harvard Medical School and director of the New England Centenarian Study. "Now they' re realizing it' s an opportunity." High-tech medicine isn't likely to change the outlook dramatically; drugs and surgery can do only so much to sustain a body once it sr. arts to fail. But there is no question we can lengthen our lives while shortening our deaths. The tools already exist, and they're within virtually everyone's reach.
Life expectancy in the United States has nearly doubled since a century ago—from 47 years to 76 years. And though centenarians are still rare, they now constitute the fastest-growing segment of the U.S. population. Their ranks have increased 16-fold over the past six decades—from 3,700 in 1940 to roughly 61,000 today. The Census Bureau projects that 1 in 9 baby boomers (9 million of the 80 million people born between 1946 and 1964) will survive into their late 90s, and that1 in 26 (or 3 million) will reach 100. “A century ago, the odds of living that long were about one in 500," says Lynn Adler, founder of the National Centenarian Awareness Project and the author of "Centenarians: The Bonus Years." "That's how far we've come."
If decrepitude were an inevitable part of aging, these burgeoning numbers would spell trouble. But the evidence suggests that Americans are living better, as well as longer. The disability rate among people older than 65 has fallen steadily since the early 1980s, according to Duke University demographer Kenneth Manton, and a shrinking percentage of seniors are plagued by hypertension, arteriosclerosis and dementia. Moreover, researchers have found that the oldest of the old often enjoy better health than people in their 70s. The 79 centenarians in Perls's New England study have all lived independently through their early 90s, taking an average of just one medication. And when the time comes for these hearty souls to die, they don't linger. In a 1995 study, James Lubitz of the Health Care Financing Administration calculated that medical expenditures for the last two years of life—statistically the most expensive—average 22,600 for people who die at 70, but just ＄8,300 for those who make it past 100.
These insights have spawned a revolution in the science of aging. "Until recently, there was so much preoccupation with diseases that little work was done on the characteristics that permit people to do well," says Dr. John Rowe, the New York geriatrician who heads the MacArthur Foundation's Research Network on Successful Aging. Research confirms the old saying that it pays to choose your parents well. But the way we age depends less on who we are than on how we live—what we eat, how much we exercise and how we employ our minds.
The author seems to suggest that ______.
A．the aged should not go to the nursing home
B．we can lengthen our lives through high-tech medicine
C．centenarians die faster than those who are younger
D．the ever-growing segment of centenarians has caused concern
A．It can be waived if you are U.S. citizen .
B．A USC alumnus or alumna needn't pay it.
C．It is non-refundable.
D．It is ＄ 55.
At the Center for Sickle-Cell Anemia in Benin City, Nigeria, Tope' s mother learned that sickle-cell anemia is a disorder of the blood. Contrary to superstitious beliefs, it has nothing to do with witchcraft or spirits of the dead. Children inherit sickle-cell anemia from both parents. It is not contagious. There is no way you can catch the disorder from another person. Either you are born with it or you are not. Tope's mother also learned that while there is no cure, the symptoms can be treated.
Sickle-cell anemia occurs mostly in those of African. descent. Dr. I. U. Omoike, director of the Center for Sickle-Cell Anemia, told Awake !: "Nigeria has the largest black population of any nation and therefore has the largest number of sicklers of any nation. That makes this country the sickle-cell capital of the world." According to the Daily Times of Lagos, about one million Nigerians have sickle-cell anemia, and 60,000 die of it each year.
A Problem in the Blood
To understand the disorder, we need to know what blood does and how it moves through the body. An illustration helps. Imagine a country that depends on imported food to feed people living in rural villages. Trucks drive to the capital city where they are loaded with food. They leave the city along major highways, but as they enter the rural areas, the roads narrow.
If everything goes well, the trucks reach their destination, drop off their food, and then return to the city to collect more food for the next delivery. If many of the trucks break down, however, the food spoils and other trucks are blocked from passing. Then the people in the villages have little to eat.
In like manner, the red ceils in the blood travel to the lungs where they pick up a supply of oxygen-food for the body. They then leave the lungs and travel swiftly through major arteries to all parts of the body. Eventually, the "roads" become so small that the red cells can move only in single file through tiny blood vessels. It is there that they deposit their load of oxygen, which feeds the cells of the body.
A normal red blood cell is round like a coin-and moves through the smallest blood vessels quite easily. But in people who have sickle-cell anemia, the blood cells break down. They lose their round shape and take the form. of a banana or a sickle — a farmer's implement. These sickled blood cells get stuck in the small veins of the body, like a truck in the mud, blocking other red blood cells from passing. When the flow of blood to a part of the body is reduced, the oxygen supply is cut off and the result is a painful crisis.
A typical sickle-cell crisis results in cruciating pain in bones and joints. Crises are unpredictable; they can occur rarely as often as every month. When they do occur, they are distressing to both child and parent. Ihunde is a nurse Who works at the sickle-cell center. "It is not easy to manage a sickler child," she says. "I know, because my daughter has the disorder. The pain comes suddenly. She screams and cries, and I cry. Only after two or three days, maybe after a week, will the pain subside."
According to the passage, which is NOT TRUE of sickle-cell anemia？
A．It is inherited.
B．It is not contagious.
C．It can be cured.
D．It occurs mostly in Africans.
A．the angular shape of the defective blood cells
B．the cutoff of oxygen supply in parts of the body
C．the cells stuck in the blood vessels
D．eating spoiled food
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