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 ___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 ___，we refer to these occurrences an “senior moments.” ___ seemingly innocent ， this loss of mental focus can potentially have a（n） ___impact on our professional， social ， and personal___.

Neuroscientists ，experts who study the nervous system ，are increasingly showing that there's actually a lot that can be done .It ___out that the brain needs exercise in much the same way our muscles do ，and the right mental ___can significantly improve our basic cognitive ___.Thinking is ___essentially a ___of making connections in the brain .To a certain extent ，our ability to ___in marking the connections that drive intelligence is inherited . ability to ___in making the connections are made through effort and practice ，___，because these connections are made through effort and practice ， scientists believe that intelligence can expand and fluctuate ___ mental effort .

Now ， a new Web-based company has taken it a step ___and developed the first “ brain training program ” designed to actually help people improve and regain their mental ___.

The Web-based program ___ you to systematically improve your memory and attention skills . The program keeps ___of your progress and provides detailed feedback ___ your performance and improvement .Most importantly， it ___modifies and enhances the games you play to ___ on the strengths you are developing - much like a（n） ___ exercise routine requires you to increase resistance and vary your muscle use .

1.[A]where [B]when [C]that [D]why

2. [A]improves [B]fades [C]recovers [D]collapses

3. [A]If [B]Unless [C]Once [D]While

4. [A]uneven [B]limited [C]damaging [D]obsucure

5. [A]wellbeing [B]envirenment [C]relationahip [D]outlook

6. [A]turns [B]finds [C]points [D]figures

7. [A]roundabouts [B]responses [C]workouts [D]associations

8. [A]genre [B]functions [C]cicumstances [D]criterion

9. [A]channel [B]condition [C]sequence [D]process

10. [A]persist [B]believe [C]excel [D]feature

11. [A]Therefore [B]Moreover [C]Otherwise [D]However

12. [A]according to [B]regardless of [C]apart from [D]instead of

13. [A]back [B]further [C]aside [D]around

14. [A]sharpness [B]stability [C]framework [D]flexibility

15. [A]forces [B]reminds [C]hurries [D]allows

16. [A]hold [B]track [C]order [D]pace

17. [A]to [B]with [C]for [D]on

18. [A]irregularly [B]habitually [C]constantly [D]unusually

19. [A]carry [B]put [C]build [D]take

20. [A]risky [B]effective [C]idle [D]familiar