单项选择题 You are developing a Windows Communication Foundation (WCF) service. You must record all available information for the first 1,000 messages processed, even if they are malformed. You need to configure the message logging section of the configuration file. Which configuration segment should you use? （）

多项选择题 You are developing a Windows Communication Foundation (WCF) service that returns location information for authorized law enforcement agencies. The service contract is as follows: [ServiceContract] public interface IMappingService { [OperationContract] long[] GetLocationCoordinates(String cityName); [OperationContract] long[] GetLocationOfCitizen(String ssn); } Users are authenticated and impersonated. The system uses ASP.NET roles. The members of law enforcement are members of the LawEnforcement role. You need to ensure that only members of the LawEnforcement role can call these methods. What are two possible ways to achieve this goal?（） (Each correct answer presents a complete solution. Choose two.)

单项选择题 You need to modify a client application that consumes a Windows Communication Foundation (WCF) service. The service metadata is no longer available. You need to modify the previously generated proxy to include asynchronous calls to the service. What should you do? （）