单选题 Mental Activities Help Save Memory     

Doing mental activities is helpful. Reading books and writing at any age may save memory, a new __31 __finds.     

The study was conducted by some American neurologists (神经病学家). It __32__ 294 people. They were given  __33__ on memory and thinking. They had the tests once a year for six years. They were also asked to talk about their mental activities during childhood, in their youth, during middle age and at their __34__ age.     

Some of those people did mental activities both __35__ and late in life. They had a slower __36__ of decline in memory than the others. The others  __37__ did such activities. Their rate of decline in memory was 48% __38__  .

“Mental activities like reading and writing are great. They __39__ bring benefits. We shouldn’t __40__  their effects on our children, ourselves and our parents," said Robert Wilson, lead author of the study.

该空应填____.
【正确答案】 A
【答案解析】 由空前后的both和and可知,空格处需要填一个形容词和后面的late构成并列结构。根据本句句意,这里表示一些参与研究的人员做了早期和晚期的智力活动。故选A。