Answer:
There are two sisters: one gives birth to the other and she, in turn, gives birth to the first. Who are the two sisters?
The more that there is of this, the less you see. What is it?
What is yours but only used by others?
How could all of your cousins have an aunt who is not your aunt?
What is the difference between yesterday and tomorrow?
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?