单项选择题 You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. You create a Web form in the application by using the following code fragment：   01 <script runat="server">   02 protected void Button_Handler（object sender， EventArgs e）   03 {   04   // some long-processing operation.  05 }   06 </script>   07 <div>   08 <asp：ScriptManager ID="defaultScriptManager"   09   runat="server" />  10   11 <asp：UpdatePanel ID="defaultPanel"   12   UpdateMode="Conditional" runat="server">  13   <ContentTemplate>   14   <!-- more content here -->   15   <asp：Button ID="btnSubmit" runat="server" 16     Text="Submit" OnClick="Button_Handler" />   17   </ContentTemplate>   18 </asp：UpdatePanel>   19 </div>    You plan to create a client-side script code by using ASP.NET AJAX.  You need to ensure that while a request is being processed， any subsequent Click events on the btnSubmit Button control are suppressed.  Which code fragment should you insert at line 10？（）

单项选择题 You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. You write the following code fragment:   <asp:ScriptManager ID="ScriptManager1" runat="server" />   <asp:UpdatePanel ID="updateLabels" runat="server" UpdateMode="Conditional">   <ContentTemplate>   <asp:Label ID="Label1" runat="server" />   <asp:Label ID="Label2" runat="server" />   <asp:Button ID="btnSubmit" runat="server" Text="Submit"   onclick="btnSubmit_Click" />  </ContentTemplate>   </asp:UpdatePanel>   <asp:Label id="Label3" runat="server" />    You need to ensure that when you click the btnSubmit Button control, each Label control value is asynchronously updatable.  Which code segment should you use?（）

单项选择题 You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. You plan to add a custom parameter in the SqlDataSource control. You write the following code fragment：   <asp：SqlDataSource ID="SqlDataSource1" runat="server"   InsertCommand="INSERT INTO [Employee] （[Field1]， [Field2]， [PostedDate]）    VALUES （@Field1， @Field2， @PostedDate）">  <InsertParameters>   <asp：Parameter Name="Field1" />   <asp：Parameter Name="Field2" />   <custom：DayParameter Name="PostedDate" />  </InsertParameters>   </asp：SqlDataSource>    You write the following code segment to create a custom parameter class：   public class DayParameter ： Parameter { } You need to ensure that the custom parameter returns the current date and time. Which code segment should you add to the DayParameter class？ （）