Answer:
Why did the computer keep sneezing?
I can be in your body but never on your placemat. I'm always better when I'm fresh, but you'll never see me in the flesh. What am I?
What gets whiter the dirtier it gets?
I tremble at each breath of air, and yet can heaviest burdens bear. What am I?
I am gentle enough to soothe your skin, light enough to fly in the sky, strong enough to crack rocks. What am I?
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.