大学英语四级模拟试题（六）

passage　3
　　　　　american　scientists　have　developed　a　new　kind　of　wire　that　can　carry　telephone　messages　for　long　distances.　the　new　fluoride　glass　wire,　or　optical　fibre,　is　a　major　improvement　over　the　optical　fibres　now　used　in　many　modern　communication　systems.　

　　　　　present　optical　fibres　are　made　from　silica　glass.　they　are　not　costly　to　produce,　but　the　signals　carried　by　these　silica　optical　fibres　weaken　very　quickly.　a　repeater　device　must　be　built　every　50　kilometers　to　increase　or　amplify　the　signals'　strength.　such　repeater　devices　are　costly　and　they　need　electrical　power.　this　creates　special　problems　for　optical　fibre　systems　that　cross　oceans.　long　copper　wires　are　needed　to　carry　electricity　from　shore　to　repeater　devices　under　the　ocean.　repairing　the　underwater　repeaters　is　costly　and　takes　much　time.　

　　　　　the　new　fluoride　optical　fibre　is　only　a　little　bigger　around　than　a　human　hair,　yet　each　could　carry　10,000　telephone　messages　at　one　time　for　thousands　of　kilometers.　traditional　copper　telephone　wires　can　carry　only　4　messages.　and　unlike　present　silica　optical　fibres,　the　new　fluoride　glass　wires　could　carry　messages　for　thousands　of　kilometers　with　very　few,　if　any,　repeater　devices.　

　　　　　the　navy　scientists　developed　the　new　optical　fibres　for　systems　that　cross　oceans,　but　they　said　there　also　would　be　many　other　uses　for　the　fluoride　glass　wires.　the　new　optical　wires　could　be　used　for　long-distance　temperature　sensing　devices.　they　could　be　used　in　some　medical　operations.　

　　　　　scientists　caution　that　the　new　fluoride　optical　fibre　still　is　only　experiment.　researchers　have　not　yet　been　able　to　make　long　tiny　wires　from　fluoride　glass.

31.　which　of　the　following　statements　is　not　true?
　　a.　silica　optical　fibres　are　not　expensive　to　produce.
　　b.　signals　carried　by　silica　optical　fibres　are　rather　weak.
　　c.　additional　devices　are　needed　for　present　optical　fibre/fiber　systems.
　　d.　repeaters　bring　about　special　problems　for　transoceanic　communications.

32.　the　major　advantage　of　fluoride　optical　fibres/fibers　over　silica　wires　is　that　fluoride　glass　.
　　a.　needs　much　fewer,　if　any,　repeaters
　　b.　carries　more　telephone　messages
　　c.　is　less　costly　to　produce
　　d.　is　tinier

33.　the　new　glass　wire　was　designed　for　.　
　　a.　communications　systems　that　cross　oceans
　　b.　long-distance　temperature　sensing　devices
　　c.　some　medical　operations　
　　d.　replacing　silica　optical　fibres　

34.　the　fluoride　optical　fibres　is　experimental　because　the　new　glass　wire　made　so　for　.　
　　a.　is　quite　expensive
　　b.　can　not　yet　carry　enormous　messages
　　c.　still　needs　repeaters
　　d.　is　not　long　enough

35.　the　author's　main　idea　is　that　.　
　　a.　present　optical　fibres　are　made　from　silica　glass
　　b.　silica　optical　fibres　need　repeaters　to　amplify　the　signals　carried
　　c.　american　scientists　have　developed　a　new　glass　wire　to　carry　long-distance　telephone　messages
　　d.　the　new　optical　fiber　had　many　uses

passage　4
　　　　　there　is　no　doubt　that　adults,　and　even　highly　educated　adults,　vary　greatly　in　the　speed　and　efficiency　of　their　reading.　some　proceed　very　slowly　throughout;　others　dash　along　too　quickly　and　then　have　to　regress.　poor　readers　in　particular　may　lack　the　ability　to　vary　their　manner　of　reading　according　to　the　type　of　reading　matter　and　to　their　intentions　in　reading　it.　a　good　reader　can　move　at　great　speed　through　the　text　of　a　novel　or　similar　light　reading　matter.　he　may　be　able　to　skim　a　page,　picking　up　a　word　or　two　here　and　there,　and　gain　a　general　idea　of　what　the　text　is　about　without　really　reading　it.　in　reading　more　difficult　material,　with　the　intention　of　taking　in　the　whole　of　it,　he　will　proceed　more　slowly,　but　even　then　he　will　vary　his　pace,　concentrating　on　the　key　words　and　passages,　perhaps　re-reading　them　several　times　and　pass　more　quickly　over　the　remainder.　a　less　efficient　reader　tends　to　maintain　the　same　speed　whatever　the　material　he　reads.　consequently,　even　light　reading　matter　gives　him　little　pleasure　because　he　reads　so　slowly.　but　this　pace　may　be　too　fast　for　really　difficult　material　which　requires　special　concentration　at　difficult　points.　
a　type　of　reading　which　necessitates　careful　attention　to　detail　is　proofreading,　in　which　the　reader,　in　order　to　detect　misprints　in　a　sample　print,　has　to　notice　not　so　much　the　meaning　of　what　he　reads　as　the　exact　shape　and　order　of　letters　and　words　in　the　text.　this　is　extremely　difficult　for　most　people,　since　they　are　accustomed　to　overlooking　such　details.　in　fact,　considerable　practice　is　required　to　practise　this　task　efficiently　and　it　can　be　done　only　be　reading　very　slowly,　and　by　paying　comparatively　little　attention　to　the　general　meaning　of　the　text.

36.　the　author　claims　that　there　is　a　difference　in　reading　speed　.
　　a.　among　readers　who　have　different　experience.　
　　b.　among　all　the　readers.　
　　c.　between　the　poorly　educated　and　the　highly　educated.　
　　d.　among　the　highly　educated　people　

37.　a　good　reader　is　a　reader　who　.　
　　a.　concentrates　on　the　wonderful　part　of　the　article　
　　b.　always　reads　slowly　and　carefully　
　　c.　changes　his　speed　according　to　the　kind　of　text　
　　d.　changes　his　speed　according　to　the　interesting　of　the　text.

38.　the　author　says　that　when　reading　a　novel,　a　good　reader　can　quickly　read　.　
　　a.　every　part　of　the　book
　　b.　the　most　wonderful　part　in　the　book.　
　　c.　the　major　part　in　the　book　
　　d.　the　scientific　part　of　the　book.　

39.　the　last　two　sentences　of　the　first　paragraph　mean　that　.　
　　a.　a　reading　speed　too　slow　for　a　difficult　book　is　just　right　for　a　non-serious　one.　
　　b.　a　reading　speed　too　slow　for　a　non-serious　book　may　be　too　fast　for　a　difficult　one.　
　　c.　a　reading　speed　too　fast　for　difficult　material　is　just　right　for　a　non-serious　book　is　also　too　slow　for　a　difficult　one.　
　　d.　a　reading　speed　too　slow　for　a　non-serious　book　is　also　too　slow　for　a　difficult　one.　

40.　which　of　the　following　can　be　the　title　of　the　passage?
　　a.　reading　and　listening　
　　b.　difference　between　highly-educated　and　poorly　educated　
　　c.　practice　reading　skill
　　d.　difference　in　the　speed　and　efficiency　of　reading