Answer:
How many bricks does it take to complete a building made of brick?
What has holes on each side, but can still can hold water?
It's what light turns into in the night
How many months of the year have 28 days?
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.
If itβs information you seek, come and see me. If itβs pairs of letters you need, I have consecutively three. What am I?