You are creating a Windows Forms application by using the .Net Framework 3.5.You create an instance of a Backgroundworker component named backgroundWorker1 to process operations that take a long time.You discover that when the application attempts to report the progress，you receive a System.InvalidOperationException exception when executing  the backgroundWorker1.ReportProgress method.You need to configure the BackgroundWorker component appropriately to prevent the application from generating exceptions.What should yo do？（）

单项选择题YouarecreatingaWindowsFormsApplicationbyusingthe.NETFramework3.5.Youplantodesignanewcontrolthatwillbeusedonmultipleformsintheapp.Youneedtoensurethatthecontrolmeetsthefollowingrequirement（1）ItretrievesdatafromaMSSQLServer2008databaseinstance.（2）ItusesWPFclassestodisplaydata.（3）Itusesuser-customizableactionswhenthecontrolisfirstpaintedontheform.Whatshouldyoudo？（）

A.Create a new custom class for the control that is derived from the Control class.
B.Create a new custom class for the control that is derived from the UserControl class.
C.Create a new custom class for the control that is derived from the ContentControl class.
D.Create a new custom class for the control that is derived from the ContentPresenter class.

多项选择题YouaredevelopingaWindowsFormsApplicationbyusingthe.NETFramework3.5.YouplantocreateacustomizedPrintPreviewdialogboxintheapplication.Youneedtoensurethatuserscanpreviewtheirdocumentsbeforeprinting.Whichtwoactionsshouldyouperform？（）

A.Add a PrintPreviewDialog control to the form.
B.Add a PrintPreviewControl control to the form.
C.Create and initialize a PrintDocument object on the form and then implement the PrintPage event handler.
D.Create and initialize a PrintDocument object on the form and then implement the BeginPrint event handler.
E.Set the Document property of the PrintPreviewDialog control to the PrintDocument instance that must be printed.

单项选择题YouarecreatingaWindowsFormsapplicationbyusingthe.NetFramework3.5.Youplantodisplaydetailedhelpinstructionsforeachcontrolintheform.Youcreateahelpfile.YouconfigureaHelpProvidercomponentontheform.YouneedtodisplaythehelpfileforthecontrolthatisfocusedwhentheF1keyispressed.WhichmethodoftheHelpProviderclassshouldyoucallforeachcontrol？（）

A.SetShowHelp
B.SetHelpString
C.SetHelpKeyword
D.SetHelpNavigator

单项选择题You are developing a component by using the .NET Framework 3.5.The component provides a method named PrintPayroll.The component will be installed with full trust on the computer of the user.    You need to ensure that the component can print without granting additional permissions to the calling application.Which code segment should you use？（）

A.A
B.B
C.C
D.D

单项选择题You are creating a Windows Forms application using the .NET Framework 3.5.You implement the PrintPage page event for a form.The users must be able to print the pages by using the Landscape orientation.You need to ensure that the users can set the page settings before printing.    Which code segment should you use？（）

A.A
B.B
C.C
D.D