注：指代brain
ally engaged 动脑筋，思考问题
3.第一句是主题句
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.
注：1.第一段 attention and memory 对应 alert and receptive
ve mind 思维活跃
d adj.健康的
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 dont 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.
注：ince 相信，确信
2.双引号之内句子不重要
less interest than 某事好处不如某事好处多
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.
