高一英语阅读专项：限时阅读--科普说明

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1、高一英语阅读专项：限时阅读--科普说明　　Analtimeterisaninstrumentusedinanairplanetotellthepilothowhighheisflying.　　Thealtimeterusedinmostairplanesisakindofbarometerwhichmeasuresairpressure.Atsealevelthispressureismorethan14poundsoneverysquareinchofthesurface.Thehigheryougointotheair,thelow

2、ertheairpressureis.Analtimetermeasuresthisairpressuretoshowhowhightheairplaneisabovethesealevel.　　Butthealtimeterdoesnotshowhowhightheplaneisabovetheground.Aplanemightbeflyingataheightof15,000feet,butitwouldbeonlyathousandfeetorsoabovethegroundifthelandinthatareahappened

3、tobe14.000feetabovethesealevel.　　Thepilotadjusts(调整)hisaltimetertotheactualsea-levelpressurebeforeleavingtheairportandhecorrectsitinflightbynewinformationgiventohimbyradio.Heflieshighenoughtoaboveanymountainhemaypassonhiscourse.Thebarometeraltimeteriscorrectwithinabove30

4、0feet.　　Anotherkindofaltimeter,theradioaltimeter,makesuseofradioreflection.Itcalculatestheheightoftheflyingplanebysendingoutelectricalsignalstothesurfacebelowandmeasuringthetimerequiredforthemtobounce(弹)back.Itiscorrectwithin1-5feetoverwater,butitisnotreliableoveruneven(

5、不平的)land.Bigplanesusuallyhavebothkindsofaltimeters.1.Thefollowingdrawingshowsaplaneflyingoveramountain,whichoftheheightsisgivenbythebarometeraltimeterintheplaneatthesamemoment?2.Thebarometeraltimeterwon'tworkiftheplaneflies ______.A.beyondtheatmosphere         B.abovever

6、yhighlandC.oververyunevenground        D.with1,000feetoftheground3.Supposeaplaneusingaradioaltimeterisflying10,000metersaboveahighlandwhichis4,000metersabovethesealevel.Whatreadingwillbegivenbythealtimeter?A.10,000meters.               B.4,000meters.C.14,000meters.      

7、         D.6,000meters.4.Supposeaplaneusingbothkindsofaltimetersisflyingoveramountainousareawherethelandrisesandfallsveryabruptly(陡峭的).Thepilotkeepshisplanesteadyatthesameheight.Whichkindofreadingwillyougetoneachofthealtimeters?A.Thereadingsonbothaltimeterswillremainstea

8、dy.B.Thereadingsonbothaltimeterswillriseandfallabruptly.C.Thereadingonthebarometeraltimeterwillriseandf