Read the following passage and choose the most likely answer to each of the following questions.
Researchers have established that when people are mentally engaged (投入的), biochemical (生物化学的) changes occur in the brain that allow it to act more effectively in cognitively (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 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's health and size."
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
【正确答案】：B
【题目解析】：
Fozard的观点主要集中在文章第二段，他认为经常做记忆工作对大多数人来讲并不必要，而且这种特殊的训练不如保持精神警觉那么有趣，借此可排除A、C，而保持精神警觉是他所赞成的，故参加各种精神活动是合理的，B项正确。D项在本段没有提到，排除。