以下關(guān)于混凝土收縮，正確的說法是（）
(1)收縮隨時(shí)間而增長(2)水泥用量愈小，水灰比愈大，收縮愈大(3)骨料彈性模量大級(jí)配好，收縮愈小(4)環(huán)境濕度愈小，收縮也愈小(5)混凝土收縮會(huì)導(dǎo)致應(yīng)力重分布
A、(1)、(3)、(5)A
暫無解析
PartIVTranslation
Satellitemassagershavethesameglobalcoverageassatellitetelephones,butcarrytextalone,whichcouldbeusefulforthosewithlaptopcomputers.(PassageFour)
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.
臨產(chǎn)后正常宮縮的特點(diǎn)有以下，其中哪項(xiàng)不正確
以下哪一項(xiàng)是原發(fā)性呼吸暫停而不是繼發(fā)性呼吸暫停的特征?
Thefirstparagraphisintendedto________.
