第一部分　阅读理解　(75分)

Passage　1
Until　the　twentieth　century　cigarettes　were　not　an　important　threat　(威胁)　to　public　health.　Men　used　tobacco　mainly　in　the　form　of　cigars　(雪茄烟),　chewing　tobacco,　pipe　tobacco(烟草),　and　snuff　(鼻烟).　Most　women　did　not　use　tobacco　at　all.
The　cigarette　industry　began　in　the　1870s　with　the　development　of　the　cigarette　manufacturing　machines.　This　made　it　possible　to　produce　great　numbers　of　cigarettes　very　quickly,　and　it　reduced　the　price.
Today　cigarettes　smoking　is　a　widespread　habit.　About　forty-three　percent　of　the　adult　men　and　thirty-one　percent　of　the　adult　women　in　the　United　States　smoke　cigarettes　regularly.　It　is　encouraging　to　note,　however,　that　millions　of　people　have　given　up　the　smoking　habit.　Seventy-five　percent　of　the　male　population　and　forty-six　percent　of　the　these　men　and　eleven　percent　of　the　women　have　stopped　smoking.　The　number　of　persons　who　have　given　up　smoking　is　increasing.
Men　as　a　group　smoke　more　than　women.　Among　both　men　and　women　the　age　group　with　the　highest　proportion　(比例)　of　smokers　is　the　age　group　24-44.
Income,　education,　and　occupation　all　play　a　part　in　determining　a　person's　smoking　habits.　City　people　smoke　more　than　people　living　on　farms.　Well-educated　men　with　high　incomes　are　less　likely　to　smoke　cigarettes　than　men　with　fewer　years　of　schooling　and　lower　incomes.　On　the　other　hand　if　a　well-educated　man　with　a　high　income　smokes　as　all,　he　is　likely　to　smoke　more　packs　of　cigarettes　per　day.
The　situation　is　somewhat　different　for　women.　There　are　slightly　more　smokers　among　women　with　higher　family　incomes　and　higher　education　than　among　the　lower　income　and　lower　educational　groups.　These　more　highly　educated　women　tend　to　smoke　more　heavily.
Among　teenagers　(少年)　the　pictures　is　similar.　There　are　fewer　teenager　smokers　from　upper-income,　well-educated　families　and　fewer　from　families　living　in　farm　areas.　High　school　students　who　are　preparing　for　college　are　less　likely　to　smoke　than　those　who　do　not　plan　to　continue　their　education　after　high　school.　Children　are　most　likely　to　start　smoking,　if　one　or　both　of　their　parents　smoke.

1.　Men　use　tobacco　mainly　in　________　forms　in　the　past.
○A.　one
○B.　two
○C.　three
○D.　four

2.　The　cigarette　industry　began　________.
○A.　one　hundred　years　ago
○B.　at　the　turn　of　the　century
○C.　in　the　eighteen　seventies
○D.　in　the　eighteen　century

3.　In　the　United　States　_______　smoke　cigarettes.
○A.　about　forty-three　percent　of　people
○B.　about　thirty-one　percent　of　people
○C.　only　old　people
○D.　about　forty-three　percent　of　the　grown　-　up　men　and　thirty-one　percent　of　the　grown　-up　women

4.　A　man's　smoking　habit　is　partly　determined　by　________.
○A.　his　income
○B.　his　education
○C.　his　occupation
○D.　all　of　the　above

5.　Children　_________　to　start　smoking,　if　their　parents　smoke.
○A.　are　most　likely
○B.　are　less　likely
○C.　hate
○D.　do　not　want

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
Passage　3
For　hundreds　of　years,　diseases　caused　by　lack　in　nutrition　(营养)　were　known　to　men.　Some　common　nutritional　diseases　are　beriberi　(脚气),　and　scurvy　(坏血病).　In　the　18th　century,　James　Lind,　a　Scottish　doctor,　discovered　a　cure　beriberi　-　whole　rice.
A　British　scientist　in　1906　showed　that　certain　foods　contain　substances　important　to　the　growth　and　development　of　the　body.　In　time　these　substances　were　called　vitamins,　meaning　essential　to　life.　Today　there　are　13　known　vitamins.　The　human　body　produces　only　three　of　them.
Vitamins　regulate　(调节)　the　way　the　body　changes　food　into　energy　and　living　tissues　(组织).　Each　vitamins　has　a　definite　use　and　the　lack　of　one　vitamin　can　interfere　with　the　function　of　another.　The　continued　lack　of　one　vitamin　can　cause　a　vitamin　lack　disease.
The　best　way　for　a　healthy　person　to　get　vitamins　is　to　eat　a　balanced　diet.　Eggs,　milk,　meat,　vegetables,　fruits,　and　whole　-　grain　are　the　most　common　sources　of　the　necessary　variety　of　foods.
Vitamins　help　to　speed　up　certain　chemical　reactions　in　the　body.　These　reactions　are　essential　for　health.　Without　vitamins,　these　reactions　would　occur　very　slowly　or　not　at　all.
Truly　vitamins　have　been　correctly　named　-　essential　to　good　health　and　life.

11.　Men　have　know　about　nutritional　diseases　__________.
○A.　a　long　time
○B.　in　18th　century
○C.　recently
○D.　in　1906

12.　Beriberi　is　a　type　of　_________.
○A.　food
○B.　vitamin
○C.　fruit
○D.　disease

13.　It　takes　scientists　_______　to　know　how　many　vitamins　there　are.
○A.　a　long　time
○B.　a　few　years
○C.　a　short　time
○D.　a　number　of　experiments

14.　Human　body　produces　__________　kinds　of　vitamins.
○A.　all　kinds　of
○B.　five
○C.　thirteen
○D.　three

15.　Eating　_______　is　the　best　way　to　get　vitamins.
○A.　few　things
○B.　vegetables
○C.　fruits
○D.　many　kinds　of　food