You create a Windows Communication Foundation (WCF) service. It is deployed on Microsoft Internet Information Services (IIS) with an application pool running as Network Service. You enable WMI tracing before launching the service. Your IT support staff adds WMI data collection through ASP.NET WMI tracing.You need to restrict the collection of WMI data to a privileged account.
What should you do in WMI Control in the Computer Management console?（）

You are developing a Windows Communication Foundation (WCF) service that does not operate on a duplex channel.You find that operations do not start until all previous operations have finished. The service hosting code contains the following lines.var service = new WarehouseService(); var host = new ServiceHost(service);You need to ensure that new operations do not wait for previous operations to finish.
Which attribute should you use to decorate the service?（）