混凝土的强度中最大的是
A、抗拉强度B
暂无解析
关于体格检查内容不包括的是
正常产程进展的标志是
临产的重要标志是
Passage4
Questions16to20arebasedonthefollowingpassage:
Successfulinnovationshavedrivenmanyoldertechnologiestoextinctionandhaveresultedinhigherproductivity,greaterconsumptionofenergy,increaseddemandofrawmaterials,acceleratedflowofmaterialsthroughtheeconomyandincreasedquantitiesofmetalsandothersubstancesinuseeachperson.Thehistoryofindustrialdevelopmentaboundswithexamples.
In1870,horsesandmulesweretheprimesourceofpoweronU.S.farms.Onehorseormulewasrequiredtosupportfourhumanbeingsaratiothatremainedalmostconstantformanydecades.Atthattime,hadanationalcommissionbeenaskedtoforecastthepopulationfor1970,itsanswerprobablywouldhavedependedonwhetheritsconsultantswereofaneconomicortechnologicalturnofmind.Hadtheybeen“economists”,theywouldprobablyhaveprojectedthe1970horsesormulepopulationtobemorethan50million.Hadtheybeen“technologists”,theywouldhaverecognizedthatthepowerofsteamhadalreadybeenharnessedtoindustryandtolearnandoceantransport.Theywouldhaverecognizedfurtherthatitwouldbetheprimesourceofpoweronthefarm.Itwouldhavebeendifficultforthemtoavoidtheconclusionthatthehorseandmulepopulationwoulddeclinerapidly.
16.Accordingtothepassage,whatsuppliedmostofthepoweronU.S.farmsin1870?
A.AnimalsB.HumansC.EnginesD.Water
17.WhichofthefollowingisNOTmentionedbytheauthorasaconsequenceofnewtechnologicaldevelopments?
A.Oldertechnologiesdieaway.
B.ThequalityoflifeisImproved.
C.Overallproductivityincrease.
D.Morerawmaterialsbecomenecessary.
18.Itcanbeinferredfromthepassagethatby1870.
A.technologybegantobemoreeconomical
B.thesteamenginehadbeeninvented
C.theU.S.horsepopulationwasabout10million
D.anationalcommissionwasabout10million
19.Inthesecondparagraph,theauthorsuggeststhat“economists”would.
A.plantheeconomythroughyearlyforecasts
B.failtoconsidertheinfluenceoftechnologicalinnovation
C.valuetheeconomiccontributionoffarmanimals
D.consultthenationalcommissionontheeconomy
20.Whatistheauthor’sattitudetowardchangesbroughtonbytechnologicalinnovations?
A.Heisexcitedaboutthem.
B.Heacceptthemasnatural.
C.Heisdisturbedbythem.
D.Hequestionstheirusefulness.
衡量胎先露下降程度的重要指标是: