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_________