ReadthefollowingpassageandmarktheletterA,B, C,orD onyouranswersheettoindicatethecorrectanswertoeachofthe questions.

WhenJohnMillswasgoingtoflyinanaeroplaneforthefirsttime,hewas frightened.Hedidnotliketheideaofbeingthousandsoffeetupintheair.“I alsodidn‟tlikethefactthatIwouldn‟tbeincontrol,”saysJohn.“I‟materrible passengerinthecar.Whensomebodyelseisdriving,Itellthemwhattoso.It driveseverybodycrazy.”HoweverJohncouldn‟tavoidflyinganylonger.It wastheonlywayhecouldvisithisgrandchildreninCanada.“Ihadmadeup mymindthatIwasgoingtodoit,Icouldn‟tletmyson,hiswifeandtheirthree childrentravelallthewayheretovisitme.Itwouldbesoexpensiveforthem andIknowTom‟sbusinessisn‟tdoingsowellatthemoment–itwouldalso be tiring for the children– it‟s a nine-hourflight!” he says.TogetreadyfortheflightJohndidlotsofreadingaboutaeroplanes.When hebookedhisseat,hewastoldthathewouldbeflyingonaBoeing747,which isbetterknownasajumbojet.“Ineededtoknowasmuchaspossiblebefore gettinginthatplane.Isupposeitwasawayofmakingmyselffeelbetter.The Boeing747isthelargestpassengeraircraftintheworldatthemoment.The firstoneflewonFebruary9th1969intheUSA.Itcancarryupto524 passengersand3.400piecesofluggage.Thefuelforaeroplanesiskeptinthe wingsandthe747’swingsaresobigthattheycancarryenoughfuelforan averagecartobeabletotravel16,000kilometresayearfor70years.Isn‟tthat unbelievable?EventhoughIhaddiscoveredallthisveryinteresting informationaboutthejumbo,whenIsawitforthefirsttime,justbeforeIwas goingtotraveltoCanada,Istillcouldn‟tbelievethatsomethingsoenormous wasgoingtogetupintheairandfly.IwasevenmoreimpressedwhenIsaw how bigitwas insidewith hundreds ofpeople!” Thebiggest surprise ofallfor Johnwastheflightitself.“Thetake-offitselfwasmuchsmootherthanI expectedalthough I was stillquite scareduntilwe wereinthe air.Inthe end, I managedtorelax,enjoythefoodandwatchoneofthemoviesandtheview fromthewindowwasspectacular.Ievenmanagedtosleepforawhile!Of course,”continuesJohn,“thebestrewardofallwaswhenIarrivedinCanada andsawmysonandhisfamily,particularlymybeautifulgrandchildren. Suddenly,IfeltsosillyaboutalltheyearswhenIcouldn‟teventhinkofgetting onaplane.IhadletmyfearoflivingstopmefromseeingthepeopleIlove most in the world. I can visit my son and family as often as I like now!”

Why is noise difficult to measure?