$chool i$ really gre
Love,
Your $on.
After receiving his son's letter, the father immediately replies by sending a letter back.
Dear Son,
I kNOw that astroNOmy, ecoNOmics, and oceaNOgraphy are eNOugh to keep even an hoNOr student busy. Do NOt forget that the pursuit of kNOwledge is a NOble task, and you can never study eNOugh.
Love,
Dad