单项选择题
A.while（ar.AsyncWaitHandle==null）{DoWork（）；}dr=cmd.EndExecuteReader（ar）；
B.while（!ar.IsCompleted）{DoWork（）；}dr=cmd.EndExecuteReader（ar）；
C.while（Thread.CurrentThread.ThreadState==ThreadState.Running）{DoWork（）；}dr=cmd.EndExecuteReader（ar）；
D.while（!ar.AsyncWaitHandle.WaitOne（））{DoWork（）；}dr=cmd.EndExecuteReader（ar）；
单项选择题 You create an application. The application processes hundreds of XML documents per minute. The XML documents are validated against inline schemas. You need to load XML documents from the file system and read them as quickly as possible. XML comments must be ignored while reading the XML documents.What should you do? （）
单项选择题 You are transferring records from one database to another. You need to decide whether you can use the SqlBulkCopy class to transfer the records. What should you do? （）
单项选择题 You are creating a Web Form. The Web Form allows users to rename or delete products in a list. You create a DataTable named dtProducts that is bound to a GridView. DataTable has the following four rows. dtProducts. Rows[0]["ProductName"] = “Soap”;dtProducts. Rows[1][“ProductName”]= “Book”;dtProducts. Rows[2][“ProductName”]= “Computer”;dtProducts. Rows[3][“ProductName”]= “Spoon”;dtProducts. AcceptChanges(); The user utilizes a Web Form to delete the first product. You need to set the RowStateFilter property of the DataTables DefaultView so that only products that have not been deleted are shown. To which value should you set the DataTabless DefaultView.RowStateFilter? （）