in-order.cs

void Main()
{
	var factory = new System.Threading.Tasks.TaskFactory();
	Console.WriteLine("Create empty task");
	var basicTask = factory.StartNew(() => { });
	Console.WriteLine("Queueing first message");
	basicTask = basicTask.ContinueWith(t => { Thread.Sleep(3000); Console.WriteLine("First message"); });
	Console.WriteLine("Queueing second message");
	basicTask = basicTask.ContinueWith(t => { Thread.Sleep(1000); Console.WriteLine("Second message"); });
	Console.WriteLine("All message are queued");
}

out-of-order.cs

void Main()
{
	var factory = new System.Threading.Tasks.TaskFactory();
	Console.WriteLine("Queueing first message");
	factory.StartNew(() => { Thread.Sleep(3000); Console.WriteLine("First message"); });
	Console.WriteLine("Queueing second message");
	factory.StartNew(() => { Thread.Sleep(1000); Console.WriteLine("Second message"); });
	Console.WriteLine("All message are queued");
}