Researchers have established that when people are mentally engaged,biochemical changes occur in the brain that allow it to act more effectively in cognitive(认知的) areas such as attention and memory.This is true regardless of age.
People will be alert and receptive if they are faced with information that gets them to think about things they are interested in. And someone with a history of doing more rather than less will go into old age more cognitively sound than someone who has not had an active mind.
Many experts are so convinced of the benefits of challenging the brain that they are putting the theory to work in their own lives.“The idea is not necessarily to learn to memorize enormous amounts of information,” says James Fozard,associate director of the National Institute on aging.“Most of us don’t need that kind of skill.Such specific training is of less interest than being able to maintain mental alertness.”Fozard and others say they challenge their brains with different mental skills,both because they enjoy them and because they are sure that their range of activities will help the way their brains work.
Gene Cohen,acting director of the same institute,suggests that people in their old age should engage in mental and physical activities individually as well as in groups. Cohen says that we are frequently advised to keep physically active as we age,but older people need to keep mentally active as well.Those who do are more likely to maintain their intellectual abilities and to be generally happier and better adjusted.“The point is ,you need to do both.”Cohen says,“Intellectual activity actually influences brain-cell health and size.”
1.People who are cognitively healthy are those____ .
A)who can remember large amounts of information
B)who are highly intelligent
C)whose minds are alert and receptive
D)who are good at recognizing different sounds
答案： C
解析：参见第二段，第二句中的doing指从事第一句的if 从句中描述的脑力活动，这些活动将使人alert and receptive,而本句中进一步说这样做的人将more cognitively sound。sound和本项的healthy是同义词。第三段中的引语说明只要常动脑就行，并不要求老人做智力要求高的事，故A、B两项皆错。D项中信息文中没提到。
2.According to Fozard’s argument,people can make their brains work more efficiently by ____ .
A)constantly doing memory work
B)taking part in various mental activities
C)going through specific training
D)making frequent adjustments
答案： B
解析：A项错，因在第三段的直接引语中，Fozard已指出持续做记忆方面的活动没有必要。C项错，因为第三段的直接引语中说，Such specific training is of less interest than being able to maintain mental alterness可见specific training无必要。D项也错，因文中只有better adjusted,没提任何frequent adjustments.
3.The findings of James and other scientists in their work____ .
A)remain a theory to be further proved
B)have been challenged by many other experts
C)have been generally accepted
D)are practised by the researchers themselves
答案：D
解析：参见第三段第一句，句中putting the theory to work in their own lives意为“让理论在自己的生活中发挥作用”。
4.Older people are generally advised to ____ .
A)keep fit by going in for physical activities
B)keep mentally active by challenging their brains
C)maintain mental alertness through specific training
D)maintain a balance between individual and group activities
答案：A
解析：从第四段第二句可知，多做体育活动是对老年人的一个普遍建议。
5.What is the passage mainly about?
A)How biochemical changes occur in the human brain.
B)Why people should keep active not only physically but also mentally.
C)How intellectual activities influence brain-cell health.
D)Why people should receive special mental training as they age.
答案： B
解析：全文都体现这一观点，最后一段是对这一概括的极好支持
