Badteethcanbepainful--andworse.Theycanevenbedeadly.Infections(感染)ofthegums(牙龈)andtheteethcancausebacteria(细菌)togointothebloodsystem.Thosebacteriacanincreasethechanceofaheartattackandworse

　　Badteethcanbepainful--andworse.Theycanevenbedeadly.Infections(感染)ofthegums(牙龈)andtheteethcancausebacteria(细菌)togointothebloodsystem.Thosebacteriacanincreasethechanceofaheartattackandworsentheeffectsofotherdiseases.Andadultsarenottheonlyonesatrisk.

　　Forexamplein2007doctorsintheWashingtonareasaidaboydiedwhenatoothinfectionspreadtohisbrain.Theysaiditmighthavebeenpreventedhadhereceivedthedentalcare(牙齿保健)heneeded.Hewastwelveyearsold.

　　ExpertsattheNationalInstitutesofHealthsaygooddentalcarestartsatbirth.Breastmilktheysayisthebestfoodforthehealthydevelopmentofteeth.Breastmilkcanhelpslowthegrowthofbacteriaandacidproductioninthemouth.

　　Butdentistssayababy'sgumsandearlyteethshouldbecleanedaftereachfeeding.Useaclothwithalittlewarmwater.Dothesameifababyisfedwithabottle.Expertssayifyoudecidetoputyourbabytosleepwithabottleonlygivethechildwater.

　　Whenbabyteethbegintoappearyoucancleanthemwithawettoothbrush.Dentistssayitisimportanttofindsofttoothbrushesmadeespeciallyforbabiesandtousethemverygently.

　　Theuseoffluoride(氟化物)toprotectteethiscommoninmanypartsoftheworld.Forexampleitisoftenaddedtodrinkingwatersupplies.Thefluoridemixeswithenamel(珐琅质)thehardsurfaceonteethtohelppreventholesfromforming.

　　【小题1】Whichofthefollowingcanbeusedasthetitleofthepassage?

　　A．ConcernsforHealthyTeethoftheYoungB．CausesofTeethProblemC．ImportanceofHealthyTeethofAllD．SolutionstoTeethProblem【小题2】What'sthemainideaofparagraph4and5?A．Howtodevelopbabies'teeth.B．Howtokeepbabies'teethcleanC．Whytoprotectbabies'teethD．Whytokeepbabies'teethclean【小题3】Thepassageindicatesthat______.A．EnamelismostwidelyusedtoprotectteethintheworldB．Breastmilkcancurebabies'badteethC．BadteethmayaffectthehealthofadultsandtheyoungD．Babies'teethshould