Passage　2 
Many　of　us　believe　that　a　person’s　mind　becomes　less　active　as　he　grows　older.　But　this　is　not　true,　according　to　Dr.　Jarvik,　professor　of　psychiatry　(精神病学)　at　the　University　of　California.　She　has　studied　the　mental　functioning　of　aging　persons　for　several　years.　For　example,　one　of　her　studies　concerns　136　pairs　of　identical　twins　(孪生儿),　who　were　first　examined　when　they　were　already　60　years　old.　As　Dr.　Jarvik　continued　the　study　of　the　twins　into　their　70s　and　80s,　their　minds　did　not　generally　decline　as　was　expected. 
However,　there　was　some　decline　in　their　psycho-motor　speed.　This　means　that　it　took　them　longer　to　accomplish　mental　tasks　than　it　used　to.　But　when　speed　was　not　a　factor,　they　lost　very　little　intellectual　ability　over　the　years.　In　general,　Dr.　Jarvik’s　studies　have　shown　that　there　is　no　decline　in　knowledge　or　reasoning　ability.　This　is　true　not　only　with　those　in　their　30s　and　40s,　but　with　those　in　their　60s　and　70s　as　well. 
It　is　true　older　people　themselves　often　complain　that　their　memory　is　not　as　good　as　it　once　was.　However,　much　of　what　we　call　’loss　of　memory’　is　not　that　at　all.　There　was　usually　incomplete　learning　in　the　first　place.　For　example,　the　older　person　perhaps　had　trouble　hearing,　or　poor　vision,　or　inattention,　or　was　trying　to　learn　the　new　thing　at　too　fast　a　pace.　In　the　cases　where　the　older　person’s　mind　really　seems　to　become　less　active,　it　is　not　necessarily　a　sign　of　becoming　less　active　due　to　old　age.　Often　it　is　simply　a　sign　of　a　depressed　emotional　(压抑的感情)　state.　 
6.　According　to　Dr.　Jarvik’s　studies,　middle-aged　and　older　persons　would　expect　to　__________. 
○A.　remember　less 
○B.　reason　better 
○C.　learn　fewer　new　things 
○D.　lose　no　intellectual　ability 

7.　Mental　decay　due　to　aging　is　_________. 
○A.　common 
○B.　much　more　common　than　most　people　believe 
○C.　much　less　common　than　most　people　believe 
○D.　true　of　those　over　sixty 

8.　A　long-term　study　of　136　pairs　of　twins　showed　that　_________. 
○A.　they　lost　a　little　ability　to　reason　over　the　years 
○B.　they　only　factor　which　decline　over　the　years　was　their　speed　with　which　to　perform　mental　tasks 
○C.　their　memory　was　not　as　good　as　it　had　once　been 
○D.　their　minds　became　a　bit　more　active　as　they　grew　older 

9.　According　to　the　passage,　all　the　following　are　instances　of　’incomplete　learning’　except　_________. 
○A.　poor　hearing 
○B.　bad　eyesight 
○C.　lack　of　attention 
○D.　the　attempt　to　learn　too　many　new　things 

10.　What　we　call　mental　decay　is　usually　a　sign　of　_________. 
○A.　a　low-spirited　state 
○B.　a　worsening　state　of　health 
○C.　old　age 
○D.　nervous　tension