可以抽象类继承另一个抽象类c#

我是C#和EF的初学者.在设计我的新样本应用程序时,我有一个愚蠢的疑问.抽象是否可以继承另一个抽象类

using System;
using System.ComponentModel.DataAnnotations;

namespace Spark.BusinessObjects.Common
{
   public abstract class BOBase
   {
    public virtual int UpdatedBy { get; set; }

    [DataType(DataType.DateTime)]
    public virtual DateTime UpdatedOn { get; set; }
 }

  public abstract class MasterBOBase : BOBase
 {
    public virtual int CreatedBy { get; set; }

    [DataType(DataType.DateTime)]
    public virtual DateTime CreatedOn { get; set; }
 }
}

namespace Spark.BusinessObjects.UserManagement
{
 using System;
using System.Data.Linq.Mapping;
using System.ComponentModel.DataAnnotations;

using Spark.BusinessObjects.Common;

[Table(Name = "tblUser")]
public class User:BOBase
{
    [Key]        
    public virtual int UserID { get; set; }

    [StringLength(maximumLength:40,MinimumLength=10)]
    [DataType(DataType.EmailAddress)]
    public virtual string EMailID { get; set; }

    [StringLength(maximumLength: 20, MinimumLength = 6)]
    [DataType(DataType.Password)]
    public virtual string Password { get; set; }

    [StringLength(maximumLength: 20, MinimumLength = 3)]
    public virtual string FirstName { get; set; }

    [StringLength(maximumLength: 20, MinimumLength = 1)]
    public virtual string LastName { get; set; }

    [DataType(DataType.Date)]
    public virtual DateTime DOB { get; set; }

}

public class UserRole:MasterBOBase
{
    [Key]
    public virtual int UserID { get; set; }
    public virtual  int UserRoleName { get; set; }
}
}

我的主表中不需要CreatedBy和CreatedOn属性.我可以像上面一样使用.这是对的吗？