Running out of air, Robert swam quickly to the surface to catch his breath.
Explanation:
An answer for this is:
"The world is very very big!
There are so much mysteries!
There is so much fun as dangerous things! More and more things you learn about world and its complexities, more and more things you understand that you don't know about them! But... You will never understand it completely!
can you please explain your question a little more into detail
