Smart aleck

there was tis smart aleck sen tis e-mail 2 his dad fr college:
Dear dad,
i am making lot$ of friend$ n $tudying like nobody'$ bu$ine$$ n i am $imply $o happy $ince i came 2 college.$end mu love n ki$$e$ 2 mum n my cute $i$ter.
Love
Your $on

d dad replied as follows:

dear son
I kNOw tat astroNOmy, ecoNomies,n oceaNOgraphy are eNOugh2 keep an hoNOur's student busy. Do NOt forget d persuit of kNOwledge is a NOble task .
Love
your dad.