Añade un argumento en tu idiomaScientists and film makers take us to the bottom of the Great Lakes and show us what the bottoms are like and go back in history when they formed.Scientists and film makers take us to the bottom of the Great Lakes and show us what the bottoms are like and go back in history when they formed.Scientists and film makers take us to the bottom of the Great Lakes and show us what the bottoms are like and go back in history when they formed.