#1)
The world is a mirror
What's looking at you
If you smile in front of it
it will smile back at you
What goes around comes around
What goes up, must come down
So sing in love and harmony
And you'll see what wonderful song

#2)
I see women and men
Both old and young
Trying to make it work
It's the hope and dream of a better day
The hope of a better world
Like the sun in heaven
What shines with a smile
Each hour and every day 
We gotta wake up with a smile
And optimism will rule the day

Ref)
Your smile is infectious
it walks around and around and around
so infectious
it passes on and on...