public Student[] Students{get;set;}
public string Name {get;set;}
public static void Main()
new School(){ Students = new [] { new Student(){ Name="Bob"}, new Student(){ Name="Jack"} }},
new School(){ Students = new [] { new Student(){ Name="Jim"}, new Student(){ Name="John"} }}
var allStudents = schools.SelectMany(s=> s.Students);
foreach(var student in allStudents){
Console.WriteLine(student.Name);