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 flies without wings? What passes all things? What mends all sorrow? What brings the morrow?
My first is a creature whose breeding is unclear. My second, a price you must pay. My whole can be found in the river of Time and refers to events of today.
Who is that with a neck and no head, two arms and no hands? What is it?
What has 13 hearts but none beat?
What is so fragile that saying its name breaks it?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?