As many people hit middle age,they often start to notice that their memory and mental clarity are not what they used to be.We suddenly can’t remember___1___we put the keys just a moment ago,or an old acquaintance’s name,or the name of an old band we used to love.As the brain___2___,we refer to these occurrences as“senior moments.”___3___seemingly innocent,this loss of mental focus can potentially have a（n）___4___impact on our professional,social,and personal___5___.Neuroscientists,experts who study the nervous system,are increasingly showing that there’s actually a lot that can be done.It___6___out that the brain needs exercise in much the same way our muscles do,and the right mental___7___can significantly improve our basic cognitive___8___.Thinking is essentially a___9___of making connections in the brain.To a certain extent,our ability to___10___in making the connections that drive intelligence is inherited.___11___,because these connections are made through effort and practice,scientists believe that intelligence can expand and fluctuate___12___mental effort.Now,a new Web-based company has taken it a step___13___and developed the first“brain training program”designed to actually help people improve and regain their mental___14___.The Web-based program___15___you to systematically improve your memory and attention skills.The program keeps___16___of your progress and provides detailed feedback___17___your performance and improvement.Most importantly,it___18___modifies and enhances the games you play to___19___on the strengths you are developing—much like a（n）___20___exercise routine requires you to increase resistance and vary your muscle use.（8）选？
上下文语义衔接+词义辨析本句句意为“而且适当的脑力锻炼可以显著地提高我们的基本认知_____。”根据上下文语意可知，通过脑力锻炼，提高老年人的记忆力，由此可知，脑力锻炼能够提高认知的功能，选项D符合句意，为正确答案。选项A B C均不符合上下文语意。genre多指的是文学或艺术作品的题材或类型，如果和cognitive搭配，则意义不通。作者在后面开始讨论thinking即思考在大脑中的地位，所以这里指的是大脑基本的认知功能，而不是认知标准或认知环境，可排除选项BC。
