职称英语考试

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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 scoreas 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 thehippocampus, a region of the brain that plays a key role in learning andmemory.

The finding suggest that even cortisol levelsin the normal, "healthy" range can actually accelerate brain aging.

The study results "now pride substantialevidence that long-term exposure to adrenal stress hormones may promotehippocampal aging in normal elderly humans, " write Nada Porter and PhilipLandfield 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 andhis colleagues measured 24-hour cortisol levels in 51 healthy volunteers, mostof whom were in their 70s.

Despite wide variation in cortisol levels, theparticipants could be divided into three subgroups: those whose cortisolprogressively increased over time and was currently high(increasing/high);those whose cortisol progressively increased over time and was currentlymoderate(increasing/moderate); and subjects whose cortisol decreased, but wascurrently moderate(decreasing/moderate).

The researchers tested the volunteers' memoryon six people in the increasing/high category and five people in thedecreasing/moderate group. The groups did not differ on tests of immediatememory, but the increasing/high cortisol group had other memory problemscompared with those in the decreasing/moderate group.

The researchers also found that the totalvolume of the hippocampus in those in the increasing/high group was 14% lowerthan those in the decreasing/moderate group, although there were no differencesin other brain regions.

The results suggest that "… brain again can be accelerated by levels of adrenal hormones thatare not generally regarded as pathological and that variation within this normalrange is related to variation in the rate of brain aging," write Porterand Landfield. "This further suggests that chronic stress may acceleratethe worsening of hippocampus. "

1. The part of the brain important for aperson'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, thehippocampus in the brain may

A) become larger.

B) become smaller.

C) be missing.

D) be totally damaged.

3. According to the article, when people feeltoo worried or nervous or when they overwork,

A) the adrenal glands will produce a stresshormone.

B) the kidneys will produce adrenal glands.

C) the hippocampus will produce high level ofcortisol in the blood.

D) the cortisol will produce something thatmakes a poorer memory.

4. When the total volume of the hippocampusbecomes 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 if adrenal hormoneshas nothing to do with the degree of brain aging.

B) the change in the levels of adrenal hormoneshas a lot to do with the degree of brain aging.

C) the long-term stress will gradually make thehippocampus worse.

D) None of the above is correct.

试题出处：http://www.examtiku.com/shiti/162818607.html
网考网参考答案：D、B、A、C、B
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大数据分析：根据网考网与考试题库的统计分析，该试题：
24%的考友选择了A选项
36%的考友选择了B选项
33%的考友选择了C选项
7%的考友选择了D选项
考友解析与评论：
 · 大家看教材，书上原话
 · 到底谁的答案是对的呀？
 · 像这种考试，没什么技术含量，全靠运气。