Answer:
What kind of nail can be grown?
Lots of them make up a word, And lots of words are in them. It's easy when you think about it. A while ago we stamped and mailed them.
A man goes out in heavy rain with nothing to protect him from it. His hair doesn't get wet. How does he do that?
This is the main ingredient in spaghetti and Mac-ยญN-ยญCheese.
What is something yet nothing, but if you fill it up it will disappear?
People take me on walks and I run and have fun. What am I?