Softwareentitiesaremorecomplexfortheirsizethanperhapsanyotherhumanconstruct,becausenotwopartsarealike(atleastabovethestatementlevel).Iftheyare,wemakethetwosimilarpartsintoone,a(1),openorclosed.Inthisrespectsoftwaresystemsdifferprofoundlyfromcomputers,buildings,orautomobiles,whererepeatedelementsabound.Digitalcomputersarethemselvesmorecomplexthanmostthingspeoplebuild;theyhaveverylargenumbersofstates.Thismakesconceiving,describing,andtestingthemhard.Softwaresystemshaveordersofmagnitudemore(2)thancomputersdo.Likewise,ascaling-upofasoftwareentityisnotmerelyarepetitionofthesameelementsinlargersize;itisnecessarilyanincreaseinthenumberofdifferentelements.Inmostcases,theelementsinteractwitheachotherinsome(3)fashion,andthecomplexityofthewholeincreasesmuchmorethanlinearly.Thecomplexityofsoftwareisa(an)(4)property,notanaccidentalone.Hencedescriptionsofasoftwareentitythatabstractawayitscomplexityoftenabstractawayitsessence.Mathematicsandthephysicalsciencesmadegreatstridesforthreecenturiesbyconstructingsimplifiedmodelsofcomplexphenomena,deriving,propertiesfromthemodels,andverifyingthosepropertiesexperimentally.Thisworkedbecausethecomplexities(5)inthemodelswerenottheessentialpropertiesofthephenomena.Itdoesnotworkwhenthecomplexitiesaretheessence.Manyoftheclassicalproblemsofdevelopingsoftwareproductsderivefromthisessentialcomplexityanditsnonlinearincreaseswithsize.Notonlytechnicalproblemsbutmanagementproblemsaswellcomefromthecomplexity. 3、____
A.linear
B.nonlinear
C.parallel
D.additive
正确答案是B