4. When the driver gets sleepy
while driving, Driver Alert ______.
A. moves more regularly
B. opens the window for the driver
C. stops working properly
D. sounds more frequently and loudly
B
难度： 易 字数：266 words 标准用时：4 minutes 实际用时：_________
Alzheimer's disease is a major national
health problem. Nearly 2 million Americans over the age of 65 have Alzheimer's
disease. It is a leading cause of death among the elderly. But Alzheimer's
disease is not confined(限于)
to the aged. There may be a million or more people under the age of 65
suffering from the disease.
At one time, people
suffering from the disease were said to be "getting old". The disease
was thought to be a natural part of growing old, but it is now known that
Alzheimer's disease strikes young and old alike. It is an organic(器官的) disease that destroys brain cells.
Alzheimer's disease
affects the patient's memory, speech, and movement. In the beginning stages of
the disease, the patient may seem slightly confused. He may have trouble
speaking. Then the patient's memory begins to fail. He may forget dates,
telephone numbers, names and plans.
As the disease
progresses, the patient may not recognize family and friends. These symptoms(症状) often cause terrible anxiety in the
patient. He may feel lost and frightened. Sometimes the patient reacts with
wild and bad behavior.
In the last stages
of the disease, the patient may not be able to take care of himself. He may
have lost the ability to speak and walk.
Scientists don't know exactly what causes
Alzheimer's disease. It may be caused by a virus(病毒).
It may be caused by a poisonous substance(物质)
in the environment. At present, there is no cure for the disease. But there are
ways to slow its progress. Exercise and physical treatment can help the
patients of this disease.
