下列方法中可用于与轴和轮毂周向固定的是( ) 。

A、轴用弹性挡圈
B、轴肩
C、螺母
D、键
查看答案
正确答案:

D

答案解析:

键可用来轴上零件的周向固定,而其他选项可用于轴上零件的轴向定位。

上一题
你可能感兴趣的试题

理想的全科医疗医患关系属于

A、家长主义模型
B、企业模型
C、契约模型
D、信托模型
E、合作模型

复苏过程中评估和决策主要基于哪三个体征?

A、呼吸,血压,肤色
B、血压,肤色,心率
C、呼吸,心率,肤色
D、呼吸,血压,心率

Iftheoldmaximthatthecustomerisalwaysrightstillhasmeaning,thentheairlinesthatplytheworld’sbusiestairroutebetweenLondonandParishaveaflightontheirhands.

TheEurostartrainservicelinkingtheUKandFrenchcapitalsviatheChannelTunneliswinningcustomersinincreasingnumbers.InlateMay,itcarrieditsonemillionthpassenger,havingrunonlyalimitedservicebetweenLondon,ParisandBrusselssinceNovember1994,startingwithtwotrainsadayineachdirectiontoParisandBrussels.By1997,thecompanybelievesthatitwillbecarryingtenmillionpassengersayear,andcontinuetogrowfromthere.

FromJuly,EurostarstepsitsservicetoninetrainseachwaybetweenLondonandParis,andfivebetweenLondonandBrussels.Eachtraincarriesalmost800passengers,210oftheminfirstclass.

Theairlinesestimatethattheywillinitiallylosearound15%-20%oftheirLondon-ParistraffictotherailwaysonceEurostarstartsafullservicelaterthisyear(1995),with15trainsadayeachway.AsimilarservicewillstarttoBrussels.Thedamagewillbelimited,however,theairlinesbelieve,withpassengernumbersreturningtopreviouslevelswithintwotothreeyears.

Intheshortterm,thedamagecausedbythe1millionpeople-levelstravelingbetweenLondonandParisandBrusselsonEurostartrainsmeansthatsomeairservicesarealreadysuffering.Someofthemajorcarrierssaythattheirpassengernumbersaredownbylessthan5%andpointtotheirrivals-ParticularlyAirFrance-ashavingsufferedtheproblems.OntheBrusselsroute,therailwaycompanyhadlesssuccess,andtheairlinesreportanythingfromarounda5%droptonovisibledeclineintraffic.

Theairlines’optimismonreturningtrafficlevelsisbasedonhistoricalprecedent.BritishMidland,forexample,pointstoitsexperienceonHeathrowLeedsBradfordservicewhichsawpassengernumbersfoldby15%whenBritishRailelectrifiedandmodernizedtherailwaylinebetweenLondonandYorkshire.Twoyearslater,travelhadrisenbetweenthetwodestinationstothepointwheretheairlinewascarryingrecordnumbersofpassengers.

1.Britishairlinesconfideinthefactthat__.

A.theyaremorepowerfulthanotherEuropeanairlines.

B.theirtotallosswon’tgobeyondadropof5%passengers.

C.theirtrafficlevelswillreturnin2-3years.

D.travelingbyrailcannevercatchupwithtravelingbyair.

2.Theauthor’sattitudetowardsthedropofpassengersmaybedescribedas__.

A.worried.B.delightedC.puzzled.D.unrivaled.

3.Inthepassage,BritishRail(Para6)ismentionedto__.

A.provideacomparisonwithEurostar.

B.supporttheairlines’optimism.

C.provetheinevitabledropofairpassengers.

D.callforelectrificationandmodernizationoftherailway.

4.Therailway’sBrusselsrouteisbroughtforthtoshowthat__.

A.theEurostartrainserviceisnotdoinggoodbusiness.

B.theairlinescanwellcompetewiththerailway.

C.theEurostartrainserviceonlycausedlittledamage.

D.onlysomeairlines,suchasAirFrance,aresuffering.

5.Thepassageistakenfromthefirstofanessay,fromwhichwemaywellpredictthatinthefollowingparttheauthorisgoingto__.

A.praisetheairlines’clear-mindedness.

B.warntheairlinesofhigh-speedrailservices.

C.proposeareductionofLondon/Parisflights.

D.advisetheairlinestofollowBritishMidlandastheirmodel.

正常产程进展的标志是

A、规律宫缩强度
B、规律宫缩频度
C、胎头下降程度及宫口扩张
D、胎心率变化

Paragraphs2and3explain________.

A、thosegoodthingsarenotwithoutsideeffects
B、whycleveradvertisingissopowerful
C、whyinmoderntimesself-medicationisstillpractised
D、whypeopledevelopfaultywaysoflife
热门试题 更多>
相关题库更多>
专业知识(暖通空调)
基础考试(暖通空调)
专业知识(给排水)
基础考试(给排水)
试卷库
试题库