甲与乙订立房屋买卖合同，甲向乙交付约定的价款，乙向甲实际支付了房屋，但未到有关部门进行登记。后来，甲将该房屋抵押于丙.该抵押()。
A、无效A
暂无解析
先兆临产表现()、胎儿下降感、()。
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.
Milk,butter,andcheeseare____herefromthefarms.
秦始皇时期，某地有甲.乙两家相邻而居，但积怨甚深.有一天，该地发生了一起抢劫杀人案件，乙遂向官府告发系甲所为.甲遭逮捕并被定为死罪.不久案犯被捕获，始知甲无辜系被乙诬告.依据秦律，诬告者乙应获下列哪种刑罚?()
分娩时最主要的产力是
