Answer:
Two brothers we are, great burdens we bear. All day we are bitterly pressed. Yet this I will say, we are full all the day, and empty when go to rest.
What stays the same size no matter how much they weight?
I follow the orders of only two. I respect the work of only two. I am in constant battles with many, Though one surpassed them all. With forces joined, We created hell, Until our mutual enemy fell. Who am I?
If eleven plus two equals one, what is nine plus five equal to?
I move without wings, Between silken string, I leave as you find, My substance behind.
As round as an apple. As deep as a cup. All the king's horses can't pull it up.