1public sealed class Singleton 2{ 3 static Singleton instance=null; 4 5 Singleton() 6 { 7 } 8 9 public static Singleton Instance 10 { 11 get 12 { 13 if (instance==null) 14 { 15 instance = new Singleton(); 16 } 17 return instance; 18 } 19 } 20}...