关于增感屏对影像效果影响的正确解释
B
增感屏对影像效果的影响，主要包括：提高影像对比度、降低影像的清晰度，并可因摄影条件的减少增加量子斑点产生的几率。
Passage4
Questions 16to 20arebasedonthefollowingpassage:
Morethan30,000driversandfrontseatpassengersarekilledorseriouslyinjuredeachyear.Atthespeedofonly30milesperhouritisthesameasfallingfromathird-floorwindows.Wearingaseatbeltsaveslives;itreducesyourchanceofdeathorseriousinjurybymorethanhalf.
Thereforedriversorfrontseatpassengersover14inmostvehiclesmustwearaseatbelt.Ifyoudonot,youcouldbefinedupto￡50.itwillnotbeuptothedriverstomakesureyouwearyourbelt.Butitwillbethedriver’sresponsibilitytomakesurethatchildrenunder14donotrideinthefrontunlesstheyarewearingaseatbeltofsomekind.
However,youdonothavetowearaseatbeltifyoureversingyourvehicle;oryouaremakingalocaldeliveryorcollectionusingaspecialvehicle;orifyouhaveavalidmedicalcertificatewhichexcusesyoufromwearingit.Makesurethesecircumstancesapplytoyoubeforeyoudecidenottowearyouseatbelt.(76)Rememberyoumaybetakentocourtfornotdoingso,andyoumaybefinedifyoucannotprovetothecourtthatyouhavebeenexcusedfromwearingit.
1.Thistextistakenfrom________.
A)amedicalmagazineB)apolicereport
C)alegaldocumentD)agovernmentinformationbooklet
2.Wearingaseatbeltinavehicle________.
A)reducesroadaccidentsbymorethanhalf
B)savesliveswhiledrivingataspeedupto30milesperhour
C)reducesthedeathrateintrafficaccidentsD)savesmorethan15,000liveseachyear
3.Itisthedriver’sresponsibilityto________.
A)makethefrontseatpassengerwearaseatbelt
B)makethefrontseatchildrenunder14wearaseatbelt
C)stopchildrenridinginthefrontseatD)wearaseatbelteachtimehedrives
4.Accordingtothetext,whichofthefollowingpeopleridinginthefrontdosnothavetowearaseatbelt?
A)Someonewhoisbackingintoaparkingspace.
B)Someonewhoispickingupthechildrenfromthelocalschool.
C)Someonewhoisdeliveringinvitationletters.
D)Someonewhoisunder14.
5.Forsomepeople,itmaybebetter________.
A)towearaseatbeltforhealthreasons
B)nottowearaseatbeltforhealthreasons
C)togetvalidmedicalcertificatebeforewearingaseatbelt
D)topayafineratherthanwearaseatbelt