[单项选择]You are creating a Window Commnunication Foundation (WCF) service application. The application needs to service many clients and requests simultaneously. The application also needs to ensure subsequent individual client requests provide a stateful conversation. You need to configure the service to support these requirements. Which attribute should you add to the class that is implementing the service?（）
A. [ServiceBehavior(lnstanceContextMode = lnstanceContextMode.PerSession, ConcurrencyMode = ConcurrencyMode.Single)]
B. [ServiceBehavior(lnstanceContextMode = lnstanceContextMode.PerCall, ConcurrencyMode = ConcurrencyMode.Reentrant)]
C. [ServiceBehavior(InstanceContextMode = lnstanceContextMode.PerSession, ConcurrencyMode = ConcurrencyMode.Multiple)]
D. [ServiceBehavior(lnstanceContextMode = lnstanceContextMode.PerCall, ConcurrencyMode = ConcurrencyMode.Multiple)]

[单项选择]You are creating a Windows Communication Foundation (WCF) service that implements operations in a RESTful manner. You need to add a delete operation. You implement the delete method as follows:void DeleteItems(string id);You need to configure WCF to call this method when the client calls the service with the HTTP DELETE operation. What should you do?（）
A. Add the WebInvoke(UriTemplate="/Items/{id}", Method="DELETE") attribute to the operation
B. Add the HttpDelete atribute to the operation
C. Replace the string parameter with a RemovedActivityAction parameter
D. Replace the return type with RemovedActivityAction.

[单项选择]You have a secured Windows Communication Foundation (WCF) service. You need to track unsuccessful attempts to access the service. What should you do?（）
A. Set the authorization Manager Type attribute of the service Authorization behavior to Message.
B. Set the include Exception Detailsln Faults attribute of the service Debug behavior to true.
C. Set the Mode attribute of the security configuration element to Message.
D. Set the message Authentication AuditLevel attribute of the service Security Audit behavior to Failure.

[单项选择] You are creating a DataTable. You use the following code segment to create the DataTable. (Line numbers are included for reference only.) 01 Dim dt As New DataTable("Products") 02 dt.Columns.Add(New DataColumn("Price", _ GetType(Decimal))) 03 dt.Columns.Add(New DataColumn("Quantity", _ GetType(Int32))) 04 Dim dc As DataColumn = New DataColumn("Total", _ GetType(Decimal)) 05 dt.Columns.Add(dc) You need to ensure that the Total column is set to the value of the Price column multiplied by the Quantity column when new rows are added or changed. What should you do? （）
A. Add the following code segment after line 05. dc.ExtendedProperties("Total") = "Price * Quantity"
B. Add the following code segment after line 05. dc.Expression = "Price * Quantity"
C. Write an event handler for the DataTable's TableNewRow event that updates the row's Total.
D. Write an event handler for the DataTable's ColumnChanged event that updates the row's Total.

[多项选择]You are creating a Web Form. You write the following code segment to create a SqlCommand object. SqlConnection conn = new.SqlConnection(connString); conn.Open（　）; SqlCommand cmd = conn.CreateCommand（　）; cmd.CommandText = “select cont(*) from Customers”; You need to display the number of customers in the Customers table. Which two code segments can you use to achieve this goal? （）
A. object customerCount = cmd.ExecuteScalar();lblCompanyName.Text = customerCount.ToString();
B. int customerCount = cmd.ExecuteNonQuery();lblCompanyName.Text = customerCount.ToString();
C. SqlDataReader dr = cmd.ExecuteReader();dr.Read();lblCompanyName.Text = dr[0].ToString();
D. SqlDataReader dr = cmd.ExecuteReader();dr.Read();lblCompanyName.Text = dr.ToString();

[单项选择] You are creating a client application and configuring it to call a Windows Communication Foundation (WCF) service.When the application is deployed, it will be configured to send all messages to a WCF routing service. You need to ensure that the application can consume the target service after the application is deployed. What should you do?（）
A. In the client application, add a service reference to the router service. In the client binding configuration, specify the address of the router service.
B. In the client application, add a service reference to the target service. In the client binding configuration, specify the address of the target service.
C. In the client application, add a service reference to the router service. In the client binding configuration, specify the address of the target service.
D. In the client application, add a service reference to the target service. In the client binding configuration, specify the address of the router service.

[单项选择] You are creating an application using Visual Studio 2010. The application consumes a Windows Communication Foundation (WCF) service.You are adding a service reference to the WCF service. You need to ensure that the generated proxy does not block the calling thread when executing a service method. What should you do when adding the service reference? （）
A. Set the Collection type to ObservableCollection.
B. Select the Reuse types in all referenced assemblies option.
C. Select the Generate asynchronous operations option.
D. Select the Always generate message contracts option.