【Eatingtoomuchfattyfoodexercisingtoolittleandsmokingcanraiseyourfutureriskofheartdisease.Butthereisanotherfactorthatcancauseyourheartproblemsmoreimmediately:theairyoubreathe.Previousstudieshavelinkedhigh】

Eatingtoomuchfattyfoodexercisingtoolittleandsmokingcanraiseyourfutureriskofheartdisease.Butthereisanotherfactorthatcancauseyourheartproblemsmoreimmediately:theairyoubreathe.

Previousstudieshavelinkedhighexposure(暴露）toenvironmentalpollutiontoanincreasedriskofheartproblembuttwoanalysesnowshowthatpoorairqualitycanleadtoheartattackorstroke(中风）withinaslittleasafewhoursafterexposure.Inonereviewoftheresearchscientistsfoundthatpeopleexposedtohighlevelsofpollutants(污染物）wereupto5%morelikelytosufferaheartattackwithindaysofexposurethanthosewithlowerexposure.AseparatestudyofstrokepatientsshowedthatevenairthattheU.S.EnvironmentalProtectionAgency(EPA)considerstobeof“moderate”(良好）qualityandrelativelysafeforourhealthcanraisetheriskofstrokeasmuchas34%within12to14hoursofexposure.

Theauthorsofbothstudiesstressthattheserisksarerelativelysmallforhealthypeopleandcertainlymodestcomparedwithotherriskfactorssuchassmokingandhighbloodpressure.Howeveritisimportanttobeawareofthesedangersbecauseeveryoneisexposedtoairpollutionregardlessoflifestylechoices.SostricterregulationbytheEPAofpollutantsmaynotonlyimproveenvironmentalairqualitybutcouldalsobecomenecessarytoprotectpublichealth.

小题1:Thetextmainlydiscussestherelationshipbetween . A．heartproblemsandairqualityB．heartproblemsandexercisingC．heartproblemsandsmokingD．heartproblemsandfattyfood小题2:Theunderlinedword“modest”inParagraph3mostprobablymeans .A．relativelyhighB．extremelylowC．relativelylowD．extremelyhigh小题3:Whatcanwelearnfromthetext? A．Eatingfattyfoodhasimmediateeffectsonyourheart.B．TheEPAconductedmanystudiesonairquality.C．ModerateairqualityismoreharmfulthansmokingD．Stricterregulationsonpollutantsshouldbemade.小题4:Theauthor’spurposeofwritingt