求解以下3道C#编程练习题

1

using System;
namespace ConsoleApp1
{
   
    public class Employee
    {
        public string num { get; set; }
        public string name { get; set; }
        public string department { get; set; }
        public Employee(string num, string name, string department)
        {
            this.num = num;
            this.name = name;
            this.department = department;
        }
    }
    public class Employee1 : Employee
    {
        public double salary { get; set; }
        public double bonus { get; set; }
        public Employee1(string num, string name, string department, double salary, double bonus) : base(num, name, department)
        {
            this.salary = salary;
            this.bonus = bonus;
        }
        public double GetTotal() { return salary + bonus; }
        public new string ToString()
        {
            return string.Format("（{0}、{1}、{2}）总输入：{3}",num,name,department,GetTotal());
        }
    }
    class MainClass
    {
        static void Main(string[] args)
        {
            var e = new Employee1("2009532", "张三", "开发部", 1080, 500);
            Console.WriteLine(e.ToString());
            Console.ReadKey();
        }
    }
}