单项选择题 You develop a service application named PollingService that periodically calls long-running procedures.These procedures are called from the DoWork method.You use the following service application code：   When you attempt to start the service， you receive the following error message： Could not start the PollingService service on the local computer.Error 1053： The service did not respond to the start or control request in a timely fashion. You need to modify the service application code so that the service starts properly.What should you do？（）

单项选择题 You are developing an application that runs by using the credentials of the end user. Only users who are members of the Administrator group get permission to run the application. You write the following security code to protect sensitive data within the application.bool isAdmin=false；  WindowsBuiltInRole role=WindowsBuiltInRole.Administrator； ......  if（!isAdmin）          throw new Exception（"User not permitted"）；   You need to add a code segment to this security code to ensure that the application throws an exception if a user is not a member of the Administrator group. Which code segment should you use？（）

单项选择题 您正在开发一个协助用户进行电子调查的应用程序。调查由25个对错判断题组成。您需要执行下列任务：将每个答案预置为是。最大程度地减少每次调查使用的内存量。您应该选择哪个存储选项？（）