Answer:
As round as an apple. As deep as a cup. All the king's horses can't pull it up.
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?
Thirty white horses on a red hill, first they champ, then they stamp, then they stand still.
We are five little objects of an everyday sort, You will find us all in a tennis court.
Half-way up the hill, I see you at last, lying beneath me with your sounds and sights. A city in the twilight, dim and vast, with smoking roofs, soft bells, and gleaming lights.
People take me on walks and I run and have fun. What am I?