简述HDV核酶的结构。
You are changing the security settings of a file named MyData.xml.You need to preserve the existing inherited access rules.You also need to prevent the access rules from inheriting changes in the future. Which code segment should you use？（） A。 B。 C。 D。
You are creating a stored procedure that will delete data from the Contact table in a SQL Server 2005 database. The stored procedure includes the following Transact-SQL statement to handle any errors that occur. BEGIN TRY BEGIN TRANSACTION DELETE FROM Person.Contact WHERE ContactID = @ContactID COMMIT TRANSACTION END TRY BEGIN CATCH DECLARE @ErrorMessage nvarchar（2000） DECLARE @ErrorSeverity int DECLARE @ErrorState int SELECT @ErrorMessage = ERROR MESSAGE（），@ErrorSeverity=ERROR SEVERITY（），@ErrorState = ERROR STATE（） RAISERROR （@ErrorMessage， @ErrorSeverity， @ErrorState） END CATCH； You test the stored procedure and discover that it leaves open transactions. You need to modify the stored procedure so that it properly handles the open transactions. What should you do？（） Add a COMMIT TRANSACTION command to the CATCH block.。 Remove the COMMIT TRANSACTION command from the TRY block.。 Add a ROLLBACK TRANSACTION command to the CATCH block.。 Add a ROLLBACK TRANSACTION command to the TRY block.。
挠度弧的画法有二种，分别是（）。 作图法和计算法。 放样法和计算法。 展开法和作图法。 垂线法和等分法。
某施工企业A由于工程建设的需要，需要经过B工厂的道路运送建筑材料。于是，A、B双方订立合同，约定施工企业A向B工厂支付一定的费用，则A企业便可以通过B单位的道路运送材料。在此合同中，施工企业A拥有的权利是（）。 相邻权。 地役权。 土地租赁权。 建设用地使用权。
You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5.
You derive a new validation control from the BaseValidator class.
The validation logic for the control is implemented in the Validate method in the following manner. protected static bool Validate(string value) {
...
}
You need to override the method that validates the value of the related control.
Which override method should you use?（）
