单项选择题 A developer is designing a web application that must support multiple interfaces， including：   • an XML web service for B2B • HTML for web-based clients • WML for wireless customers   Which design pattern provides a solution for this problem？()

单项选择题 Adeveloperisdesigningamulti-tierapplicationanddiscoversaneedtohidethedetailsofestablishingandmaintainingremotecommunicationsfromtheclient.Inaddition，theapplicationneedstofind，inatransparentmanner，theheterogeneousbusinesscomponentsusedtoservicetheclient’srequests.Whichdesignpatterns，workingtogether，addresstheseissues？（）

单项选择题 Squeaky Beans Inc. hired an outside consultant to develop their web application. To finish the job quickly， the consultant created several dozen JSP pages that directly communicate with the database. The Squeaky business team has since purchased a set of business objects to model their system， and the Squeaky developer charged with maintaining the web application must now refactor all the JSPs to work with the new system.  Which pattern can the developer use to solve this problem？（）