{ TaskManager myTasks = new TaskManager(); myTasks.AddTask("Buy Milk", "Pending"); myTasks.AddTask("Pay Bills", "Completed"); myTasks.PrintAllTaskKeys(); /* Output: Buy Milk Pay Bills */ myTasks.PrintAllTaskValues(); /* Output: Pending Completed */ myTasks.PrintAllEntries(); /* Output: Buy Milk: Pending Pay Bills: Completed */ } }3e:T62a,using System; using System.Collections.Generic; class StudentDatabase { private Dictionary> students; public StudentDatabase() { students = new Dictionary>(); } public void AddStudent(string name, Dictionary subjects) { students[name] = subjects; } public string GetMark(string name, string subject) { if (students.TryGetValue(name, out Dictionary? subjects)) { return subjects.ContainsKey(subject) ? subjects[subject] : "N/A"; } return "N/A"; } public void PrintDatabase() { foreach (KeyValuePair> student in students) { Console.WriteLine("Student: " + student.Key); foreach (KeyValuePair subject in student.Value) { Console.WriteLine($" Subject: {subject.Key}, Grade: {subject.Value}"); } } } } class Program { static void Main(string[] args) { StudentDatabase studentDb = new StudentDatabase(); studentDb.AddStudent("Alice", new Dictionary { { "Math", "A" }, { "English", "B" } }); Console.WriteLine(studentDb.GetMark("Alice", "English")); // Output: "B" Console.WriteLine(studentDb.GetMark("Alice", "History")); // Output: "N/A" studentDb.PrintDatabase(); /* Output: Student: Alice Subject: Math, Grade: A Subject: English, Grade