在下列选项中包含数据库系统中的外模式/模式映象定义的是（）

循环信用证按金额循环方式的不同，可以分为（）。

在电子货币的支付机制中，贷记卡交易支付是属于（）

Inwhatseemsliketheprehistorictimesofcomputerhistory;theearth’spostwarera,therewasquiteawidespreadrumorthatcomputerswouldtakeovertheworldfrommanoneday.Alreadytoday,lessthanfiftyyearslater,ascomputersarerelievingusofmoreandmoreoftheroutinetasksinbusinessandinourpersonallives,wearefacedwithalessdramaticbutnotlessforeseenproblem.Peopletendtobeover-trustingofcomputersandarereluctanttochallengetheirauthority.Indeed,theybehaveasiftheywerehardlyawarethatwrongbuttonsmaybepushed,orthatacomputermaysimplymalfunction.Obviously,therewouldbenopointininvestinginacomputerifyouhadtocheckallitsanswers,butpeopleshouldalsorelyontheirowninternalcomputersandcheckthemachinewhentheyhavethefeelingthatsomethinghasgonewrong.Questioningandroutinedouble-checksmustcontinuetobeasmuchapartofgoodbusinessastheywereinpre-computerdays.Maybeeachcomputershouldcomewiththewarning:forallthehelpthiscomputermayprovide,itshouldnotbeseenasasubstituteforfundamentalthinkingandreasoningskills.

37.Accordingtothepassage,theauthorwouldprobablydisapproveof__________.

A.investmentincomputers

B.completedependenceoncomputers

C.double-checkoncomputers

D.theuseofcomputer

38.Intheauthor’sopinion,peopleshould__________.

A.bereasonablydoubtfulaboutcomputers

B.usecomputersforbusinesspurposesonly

C.substitutecomputersforbasicthinking

D.checkalltheiranswerswhenusingcomputers

39.Whatissuggestedinthispassage?

A.Computerwon’tchangeourpersonallives.

B.Computercancreateunforeseenproblems.

C.Computerhastakencontroloftheworld.

D.Computercannotaffectourbusinesses.

40.Whatisthemainpurposeofthispassage?

A.Tolookbacktotheearlydaysofcomputers.

B.Toexplainwhattechnicalproblemsmayoccurwithcomputers.

C.Todiscourageinvestmentincomputers.

D.Towarnagainstamentallylazyattitudetowardscomputers.

以下关于电子商务企业降低物流成本的基本思路的论述，不正确的是（）