题目

 “Our aim is to take our art to the world and make people understand what it is to move,” said David Belle, the founder of parkour ( also called free running－a kind of extreme sport).      Do you love running? It is a good exercise, yet many people find it boring. But what if making your morning jog a creative one? Like jumping from walls and over gaps, and ground rolls? Just like the James Bond in the movie Casino Royale? Bond jumps down from a roof to a windowsill and then runs several blocks over obstacles on the way. It is just because of Bond’s wonderful performances 圆的半径与周长（　　）关系．A．成正比例B．成反比例C．不成比例D．以上答案都不对