CT 机属于（）设备。
毛泽东指出，中国革命的历史进程，必须分为（）。 ["三步","五步","两步","四步"]
You are developing a Windows Communication Foundation (WCF) service to provide an in-memory cache for many Web applications.The service contract is defined as follows. (Line numbers are included for reference only.) 01 [ServiceContract] 02 public interface IDataCache 03 { 04 ... 05 }06 07 08 public class DataCache : IDataCache 09 { 10 ... 11 } You need to ensure that all users share the cache. Which code segment should you insert at line 07?（） [" [ServiceBehavior(TransactionIsolationLevel = IsolationLevel.RepeatableRead)]"," [ServiceBehavior(InstanceContextMode = InstanceContextMode.Single)]"," [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerSession)]"," [ServiceBehavior(TransactionIsolationLevel = IsolationLevel.ReadComitted)]"]
国家对医疗器械实行分类管理，第三类是指具有（），需要采取特别措施严格控制管理以保证其安全、有效的医疗器械。
You develop a Windows Communication Foundation (WCF) service that uses basic authentication for client credentials. This service is currently configured to use message security. The service is hosted on a server in workgroup mode.Users report that their passwords are stolen when they use public computers.You need to ensure that messages are secure and users are authenticated.You prevent the service from being called over HTTP through Microsoft Internet Information Services (IIS) configuration. What should you do next?（） [" Use the transport security mode and specify None for transport client credential type."," Use the transportWithMessageCredential security mode and specify Basic for the transport client credential type."," Use the message security mode and specify Basic for the transport client credential type."," Use the transportWithMessageCredential security mode and specify None for the transport client credential type."]
什么是系统？系统的主要特征有哪些？
