Answer:
What is as big as you are and yet does not weigh anything?
Mr. Smith has two children. If the older child is a boy, what are the odds that the other child is also a boy?
What is a ten letter word that starts with gas?
How can you throw a ball 20 meters, and have it come back to you without hitting anything?
What can fill an entire room without taking up any space?
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.