Once, a circle lost a piece of its own. The circle wanted to be whole, so it went around looking for its missing piece. But it was incomplete, so it could only roll very slowly. It enjoyed the flowers and the sunshine along the way. It talked with worms. It found lots of different pieces, but none of them fit. So it left them all by the side of the road and kept on looking for the missing piece.
Then one day the circle found a piece that fit perfectly. The circle put the missing piece into itself. It could be whole with nothing missing. It was so happy and began to roll. Now that it was a perfect circle, it could roll very fast, too fast to see flowers or talk to worms. It realized how different the world was when it rolled so quickly. It felt so sad that it stopped, left its found piece by the side of the road and rolled away slowly.
Sometimes we are perfect when we lose something. A man who has everything is a poor man in some ways. He will never have hopes, dreams or something better. He will never know someone loves him or someone is giving him something he has always wanted or never had.
We couldn’t be perfect, but we must be brave enough to love, strong enough to forgive, kind enough to share happiness with others and clever enough to know there is enough love around us and then we can always live a wonderful time in our lives.

The circle rolled very slowly because it       .

A．spent much time talking to worms

B．wanted to enjoy the sunshine

C．was looking for its missing piece

D．lost a piece of its own

Why did the circle stop when it rolled quickly? Because it       .

A．wanted to enjoy the world

B．found a different world

C．wanted to look for another missing piece

D．thought the world changed so quickly

The story mainly tells us that       .

A．nobody loves us if we give nothing

B．a man who has everything is the happiest

C．losing something may not be a bad thing sometimes

D．we are not whole when we lose something