You are creating a Windows Forms application by using the .NET.Framework 3.5. You create a new form in your application.You add a SplitContainer control named spcFrame to the form. 
The SplitContainer control has two SplitterPanel controls named Panel1 and Panel2. You are configuring the SplitContainer control to define the layout of the form. You need to ensure that the following requirements are met： 
（1）The initial distance from the left edge of the spcFrame splitter is set to 200 pixels 
（2）The size of the Panel2 SplitterPanel remains unchanged when the form is resized   
Which code segment should you use？（）

单项选择题YouarecreatingaWindowsFormsapplicationbyusingthe.NETFramework3.5.Youcreateanewformintheapplication.YouaddaContextMenuStripcontrolnameddctxMenutotheform.YouhaveauserdefinedclassnamedCustomControl.Youwritethefollowingcodesegmentintheapplication（Linenumbersareincludedforreferenceonly） CustomControlmyControl=newCustomControl（）； YouneedtoensurethataninstanceofCustomControlisdisplayedontheformasatoplevelitemofthectxMenucontrol. Whichcodesegmentshouldyouadd？（）

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

单项选择题You are creating a Windows Forms application by using the .NET Framework 3.5  The application requires a form to display a clock.You need to create a circular form to display the clock. Which code segment should you use？（）

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

单项选择题YouarecreatingaWindowsapplicationbyusingthe.NETFramework3.5.YoucreateaninstanceoftheBackgroundWorkercomponentnamedbackgroundWorker1toasynchronouslyprocesstimeconsumingreportsintheapplication.Youwritethefollowingcodesegmentintheapplication（Linenumbersareincludedforreferenceonly.） Youneedtowriteacodesegmentthatreportstotheapplicationwhenthebackgroundprocessdetectsanyofthefollowingactions： （1）Anexceptionisthrown （2）Theprocessiscancelled （3）Theprocessissuccessfullycompleted Whichcodesegmentshouldyouinsert？（）

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

单项选择题You are creating a Windows application by using the .NET Framework 3.5.You plan to create a form that might result in a timeconsuming operation.You use the QueueUserWorkItem method and a Label control named lblResult.You need to update the users by using the lblResult control when the process has completed the operation. 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 for a courier company by using the .NET Framework 3.5.You create a form that allows customers to track the progress of their shipments.The form contains the following elements：  （1）A text box named txtTN that allows users to enter a tracking number.  （2）An ErrorProvider control named ErrorProvider1 that informs users of an invalid tracking number.  （3）A function named ValidTrackingNumber that validates tracking numbers.   You need to ensure that the txtTN text box is validated.   Which code segment should you use？（）

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