单项选择题
A. While ar.AsyncWaitHandle Is Nothing DoWork()End Whiledr = cmd.EndExecuteReader(ar)
B. While Not ar.IsCompleted DoWork()End Whiledr = cmd.EndExecuteReader(ar)
C. While T hread.CurrentThread.ThreadState = ThreadState.Running DoWork()End Whiledr = cmd.EndExecuteReader(ar)
D. While Not ar.AsyncWaitHandle.WaitOne() DoWork()End Whiledr = cmd.EndExecuteReader(ar)
单项选择题 You load an XmlDocument named doc with the following XML. World Atlas Dictionary You need to use an XPath query string to select the two book nodes. Which code segment should you use? （）
单项选择题 You create a Web Form. The Web Form uses the FormView control to enable a user to edit a record in the database. When the user clicks the Update button on the FormView control, the application must validate that the user has entered data in all of the fields. You need to ensure that the Web Form does not update if the user has not entered data in all of the fields. Which code segment should you use? （）
多项选择题 You create a Web Form that contains connected Web Parts. You write the following declaration in your Web Form.You need to ensure that your Web Part connection is valid. Which two actions should you perform? （）