第二篇
High Stress May Damage Memory
According to a report issued in May 1998, elderly people who consistently high blood levels of the stress hormone. What's more ,high levels of cortisol are also associated with shrinking of the hippocampus(海马区), 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(肾上腺) stress hormones may promote hippocampal aging in normal elderly humans, "write Nada porter and Phillip Landfield. Cortisol is a hormone releases in response to stress by the adrenal glands(腺), which sit on top of the kidneys (肾).
Over a 5-to 6-year period, dr. Sonia lupine and his colleagues measures 24-hour cortisol levels in 51 healthy volunteers, most whom were in their 70s.
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 in 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(病态的) 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 the hippocampus.
6 which of the following plays a key role in one's learning and memory?
A the kidneys
B the adrenal hormone
C the stress hormone
D the hippocampus
7 when the levels of cortisol go high ,the hippocampus_________.
A may expand
B may shrink
C may disappear
D may function better
8 according to the passage, when people are under stress,_________.
A the adrenal glands will produce cortisol
B the kidneys will shrink rapidly
C the hippocampus will produce cortisol
D the brain will work more efficiently
9 it app ears that when the hippocampus shrinks sue to high levels of cortisol, other brain regions_________.
A may change dramatically
B may stop functioning
C may remain unaffected
D may be seriously damaged
10 the research conducted by porter and land field showed that_________.
A the levels of adrenal hormones have nothing to do with brain aging
B changes in the levels of adrenal hormones can affect brain aging
C chronic stress may strengthen one's memory
D the rate of brain aging always remains stable
第三篇
Valuing Childhood
The value of childhood is easily blurred(模糊) in to say's world. Consider some recent developments: the child-murders in the Jonesboro, ark. Schoolyard shooting case were convicted and sentenced. Two boys, 7 and 8, were charged in the murder of an 11-year-old girl in Chicago.
Children who commit horrible crimes appear to act of their own will. Yet, as legal proceedings in Jonesboro showed, the one boy who was to address the court couldn't begin to explain his acts, though he tried to apologize. There may have been a motive - youthful jealousy and resentment. But a deeper question remains: why did these boys and others in similar trouble apparently lack any inner, moral restraint(束缚)?
That question echoes for the accused in Chicago, young as they are. They wanted the girl's bicycle, a selfish impulse(冲动) common enough among kids.
Redemption(拯救) is a practical necessity. How can value be restored to young lives distorted(扭曲) by acts of violence? The boys in Jonesboro and in Chicago will be confined in institutions for a relatively short time. Despite horror at what was done children are not cannot be dealt with as adults, not if a people wants to consider itself civilized. That's why politicians' cries for adult treatment of youthful criminals ultimately miss the point.
But the moral void(真空) that invites violence has many sources. Family instability(不稳定) contributes. So does economic stress. That void, however, can be filled. The work starts with parents, who have to ask themselves whether they're doing enough to give their children a firm sense of right and wrong. Are they really monitoring their activities and their developing processes of thought?
Schools, too, have a role in building character. So do youth organizations. So do law enforcement agencies, which can do more to inform the young about laws, their meaning. And their observance(遵守)
11 The two boys in Chicago were_________.
A shot
B murdered.
C accused.
D set free
12 The boys Jonesboro and Chicago apparently lacked a sense of_________.
A right and wrong
B humor.
C gratitude.
D safety.
13 According to politicians, when children commit crimes, they should be treated in the same way as_________.
A murderers
B criminals
C victims.
D adults.
14 Which of the following does the writer cite as a source of moral void?
A Official corruption
B Social injustice.
C Family instability.
D Racial prejudice.
15 Which of the following statements is NOT true according to the passage ?
A Parents should give their children instruction in morality.
B Schools should help create a moral sense in children.
C Law enforcement agencies should do more to help children understand laws
D youth organizations have no role to play in building character.
