Methods of the String class

What does each of the following statements do?
  1. Label2.Text = Label1.Text.ToUpper
  2. Label2.Text = Label1.Text.ToUpper.ToLower
  3. Label2.Text = Label1.Text.ToUpper.ToLower.Substring(2, 4)
  4. Label2.Text = Label1.Text.ToUpper.Substring(2, 4).ToLower
  5. Label2.Text = Label1.Text.Substring(2, 4).ToUpper.ToLower
  6. Label2.Text = Label1.Text.Substring(2, 4).Substring(0, 1).ToUpper.ToLower