兔实验安静时给予M受体阻断剂阿托品可引起心率明显增加,房室交界区传导加速。但若切断双侧迷走神经后再给予阿托品,心脏的变化为()。

A、心率明显增快
B、心率明显降低
C、心率无明显变化
D、房室传导明显增快
E、房室传导明显减慢
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正确答案:

C

答案解析:

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GriffithworkedforafirmthatspecializedineconomicdevelopmentinWashingtonD.C.becausesheneededmoneytopayforherdebt.

翻译:

中华民族的传统文化博大精深、源远流长。早在2000多年前,就产生了儒家学说和道家学说,以及其他很多在中国思想史上有地位的学说流派,这就是有名的“诸子百家”。从孔夫子到孙中山,中华民族传统文化有它的很多珍贵品质。比如“天下兴亡,匹夫有责”的爱国情操,“民为邦本”、“民贵君轻”的民本思想和“己所不欲,勿施于人”的行为准则。

ThediscoveryoftheAntarcticnotonlyprovedoneofthemostinterestingofallgeographicaladventures,butcreatedwhatmightbecalled“theheroicageofAntarcticexploration”.Bytheirtremendousheroism,mensuchasShakleton,Scott,andAmundsencausedanewcontinenttoemergefromtheshadows,andyetthatheroicage,littlemorethanacenturyold,isalreadypassing.Modernscienceandinventionsarerevolutionizingtheendurance,futurejourneysintotheseicywasteswillprobablydependonmotorvehiclesequippedwithcaterpillartractionratherthanonthedogsthatearlierdiscoverersfoundsoinvaluableandhardlycomparable.

FewrealizethatthisAntarcticcontinentisalmostequalinsizetoSouthAmerica,andenormousfieldofworkawaitsgeographersandprospectors.Thecoastsofthiscontinentremaintobeaccuratelycharted,andthemapingofthewholeoftheinteriorpresentsaformidabletasktothecartographerswhoundertakethework.Oncetheirlaborsarecompleted,itwillbepossibletoprospectthevastnaturalresourceswhichscientistsbelievewillfurnishoneofthelargesttreasurehoardsofmetalsandmineralstheworldhasyetknown,andalmostinexhaustiblesourcesofcopper,coal,uranium,andmanyotheroreswillbecomeavailabletoman.SuchdiscoverieswillusherinaneraofpracticalexploitationoftheAntarcticwastes.

Thepolardarknesswhichhidesthiscontinentforthesixwintermonthswillbedefeatedbyhugebatteriesoflight,andmakepossibletheestablishingofair-fieldsforthefutureinter-continentalairservicesbymakingtheseareasaslightasday.Presentflyingrouteswillbecompletelychanged,fortheAntarcticrefuelingbaseswillmakeflightsfromAustraliatoSouthAmericacomparativelyeasyoverthe5,000milesjourney.

Theclimateisnotlikelytoofferaninsuperableproblem,fortheexplorerAdmiralByrdhasshownthattheclimateispossibleevenformencompletelyuntrainedforexpeditionsintothosefrozenwastes.Someofhispartiesweremenwhohadneverseensnowbefore,andyetherecordsthattheysurvivedtherigorsoftheAntarcticclimatecomfortably,sothat,providedthattheappropriateinstallationsaremade,wemayassumethathumanbeingsfromallcountriescouldlivetheresafely.Byrdevenaffirmsthatitisprobablythemosthealthyclimateintheworld,fortheintensecoldofthousandsofyearshassterilizethiscontinent,andrendereditabsolutelygermfree,withtheconsequencesthatordinaryandextraordinarysicknessanddiseasesfromwhichmansuffersinotherzoneswithdifferentclimatesarehereutterlyunknown.Thereexistnoproblemsofconservationandpreservationoffoodsupplies,forthelatterkeepindefinitelywithoutanysignsofdeterioration;itmayevenbethatlatergenerationswillcometoregardtheAntarcticasthenaturalstorehouseforthewholeworld.

Plansarealreadyonfoottosetuppermanentbasesontheshoresofthiscontinent,andwhatsofewyearsagowasregardedasa“deadcontinent”nowpromisestobeamostactivecenterofhumanlifeandendeavor.

1.WhendidmanbegintoexploretheAntarctic?

A.About100yearsago.

B.Inthiscentury.

C.Atthebeginningofthe19thcentury.

D.In1798.

2.Whatmusttheexplorersbe,eventhoughtheyhavemodernequipmentandtechniques?

A.Braveandtough

B.Stubbornandarrogant.

C.Well-likedandhumorous.

D.Stoutandsmart.

3.Themosthealthyclimateintheworldis___.

A.inSouthAmerica.

B.intheArcticRegion.

C.intheAntarcticContinent.

D.intheAtlanticOcean.

4.WhatkindofmetalsandmineralscanwefindintheAntarctic?

A.Magnetite,coalandores.

B.Copper,coalanduranium.

C.Silver,naturalgasanduranium.

D.Aluminum,copperandnaturalgas.

5.Whatisplannedforthecontinent?

A.Buildingdamsalongthecoasts.

B.Settingupseveralsummerresortsalongthecoasts.

C.Mappingthecoastandwholeterritory.

D.Settinguppermanentbasesonthecoasts.

翻译训练:

要了解中国文化,就应该对中国的戏曲文化有所了解。中国地方戏种类很多,其中京剧是一个具有代表性的剧种。作为一个独立的剧种,京剧的诞生大约是在1840年至I860年。京剧是在吸收其他地方戏营养的基础上形成的。京剧有明确的角色分工;在念白上用北京方言;在音乐上以胡琴为主要伴奏乐器。由于京剧是在融合各种地方戏之精华的基础上形成的,所以它不仅为北京的观众所钟爱,也受到全国人民的喜爱。

Evenifhisletter____tomorrow,it____toolatetodoanything.

A、willarrive,,is
B、shouldarrive,,were
C、arrives,,willbe
D、arrives,,wouldbe
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