Passage4
Questions16to20arebasedonthefollowingpassage:
Thenewglobalsatellitecommunicationssystemswillofferthreekindsservice,whichmayoverlapinmanydifferentkindsofreceivers.
VOICE.SatellitetelephoneswillbeabletomakecallsfromanywhereontheEarthtoanywhereelse.Thatcouldmakethemespeciallyusefultoremote,thirdworldvillages(someofwhichalreadyusestationarysatellitetelephones),explorersanddisaster-reliefteams.Today’smobiletelephonesdependonearth-boundtransmitters,wheretechnicalstandardsvaryfromcountrytocountry.Sobusinesstravelerscannotusetheirmobilephonesoninternationaltrips.Satellitetelephoneswouldmakethatpossible.
MESSAGING.Satellitemassagershavethesameglobalcoverageassatellitetelephones,butcarrytextalone,whichcouldbeusefulforthosewithlaptopcomputers.Equippedwithasmallscreenliketoday’spapers,satellitemassagerswillalsoreceiveshortmessages.
TRACKING.Voiceandmessagingsystemswillalsotelltheiruserswheretheyaretowithinafewhundredmeters.Combinedwiththemessagingservice,thelocationservicecouldhelprescueteamstofindstrandedadventurers,thepolicetofindstolencars,exporterstofollowtheprogressofcargoes,andhaulagecompaniestocheckthatdriversarenotdetouringthepub.America’smilitaryGlobalPositioningSystem(GPS)satellitewillprovidebetterpositioninginformationtoanyonewhohasareceiverfortheirsignals,butGPSdoesnotcarrymessages,sosuchareceivercannotbeusedonitsownfortrackingorrescue.Bythemid-1990s,GPSreceiverswillbeabletotellpeoplewheretheyaretowithin70metersanywhereintheworld,andtowithinameterorsoinareaswheretheserviceissupplementedbyground-basedtransmitter.
16.Globalsatellitecommunicationssystemswillbeusefulto.
A.laptopcomputerusers
B.remotevillages
C.disaster-reliefteams
D.allabove
17.Satellitetelephonewillmake.
A.businesstravelersusemobilephonesoninternationaltrips
B.possiblecallsfromanywhereonearthtoanywhereelse
C.explorershappy
D.allabove
18.Whichofthefollowingistrue?
A.ThepositioningprecisionofthevoicesystemisbetterthanthatofGPS.
B.ThepositioningprecisionofGPSisBetterthanthatofthevoicesystem.
C.ThepositioningprecisionofthemessagingsystemisbetterthanofGPS.
D.Thepositioningprecisionofvoicesystemisbetterthanthatofthemessagingsystem.
19.Whatcanwesayaboutthenewglobalsatellitecommunicationssystems?
A.Theyarewidelyused.
B.Theyareveryhelpful.
C.Theyarecostly.
D.BothAandB.
20.Whichofthefollowingmaybethebesttitleforthepassage?
A.GlobalSatelliteCommunications
B.NewVoiceandMessagingSystem
C.NewGenerationSatellite
D.AlwaysinTouch
CDCDB
暂无解析
翻译：
The captain realized that the men tried to deceive him so he made them work very hard for the rest of the voyage. (Passage One)
The author tells us in paragraph 4 ________.
翻译：
As the source of aluminum is almost inexhaustible, we can expect that more and more uses will be found for this versatile metal. (Passage Two)