lttheydonotonlylookyoungerandslimmerbutfeelbetter.Becauseofincreasedphysicalfitnesslifeexpectanceinthenationhasrisentoseventy-threeyearswithfewerpeoplesufferingfromheartdiseasethenation'snumberoneki

　　lttheydonotonlylookyoungerandslimmerbutfeelbetter.Becauseofincreasedphysicalfitnesslifeexpectanceinthenationhasrisentoseventy-threeyearswithfewerpeoplesufferingfromheartdiseasethenation'snumberonekiller.

　　Jogging(慢跑)theeasiestandcheapestwayofimprovingthebodykeepsover30millionpeopleofallagesontherun.Forthepriceofagoodpairofrunningshoesanyoneanywherecanjointherace.

　　Dietingtoohasbecomeanational pastime.Promotersofdietsthateliminateeatingonethingoranothersuchasfatsorcarbohydrates(碳水化合物)promiseasmuchas20-poundweightlosseswithintwoweeks.Booksdescribingsuchamazingdietsalwaysheadup(居……之首)thebest-sellerlistsbecausepeoplewhoareoverweightwanttoloseweightquicklyandeasily.

　　Neverthelessjogginganddietingcarriedtoextremescanbeharmful.Manyconfusedjoggersoverdoandfinallysufferfromankleandfootdamage.Dietingfortunatelybecomesonlyatemporarymeansforsheddingafew poundswhilethebodylosethebalancednutrition(营养)itrequiressomostdieterscannotkeepondiets.Aboveallcommonsenseshouldbethekeystoneforanydietingandexerciseplan.

　　6.Themainideaofthispassageisthat___________.

　　A.bothjogginganddietingcanimproveyourhealth

　　B.exerciseandimproveddiethasraisedtheAmerican'slifeexpectance

　　C.peoplewhojoganddietwiselywillbehealthierthanthosewhodonot

　　D.dietandexerciseharmratherthanbenefit health

　　7.AccordingtothepassagewhichofthefollowingstatementsisTRUE?

　　A.Joggingcandamagethebodybecauseitistootoughanexercise.

　　B.Dietsaresopopularbecausetheyareonthebest-sellerlists.

　　C.Americansnowlivetobe73yearsold.

　　D.ExerciseanddietaremorewidespreadinAmericathaneverbefore.

　　8.Itisimpliedbutnotstatedthat___________.

　　A.heartdiseaseisthenumberonekilleramongAmericans

　　B.exerciseanddietingbringaboutspiritualaswellasphysicalwell-being

　　C.peopledon'tstayonadietbecauseitdoesn'twork

　　D.a20-poundweightlosswithintwoweeksistoomuchforthebody

　　9.Thebesttitleforthispassageis_________