ball

Serena Williams of the U.S. serves during her women's singles match against Silvia Soler-Espinosa of Spain at the China Open tennis tournament in Beijing...Serena Williams of the U.S. serves during her women's singles match against Silvia Soler-Espinosa of Spain at the China Open tennis tournament in Beijing September 29, 2014.

Petar Kujundzic/Reuters

Serena Williams of the US serves during her singles match against Spain’s Silvia Soler-Espinosa at the China Open tennis tournament in Beijing on Monday.

A boy plays with a ball at a temporary tent camp set up for Ukrainian refugees in the town of Novoshakhtinsk in Rostov region near the Russian-Ukrainian border, southern Russia, July 9, 2014.

Sergei Karpukhin/Reuters

A boy plays with a ball at a temporary tent camp set up for Ukrainian refugees in the town of Novoshakhtinsk in Rostov near the Russian-Ukrainian border, southern Russia

A man plays with a ball at sunset on June 10, 2014 in Berlin.

Inga Kjer/AFP

A man plays with a ball at sunset on Wednesday in Berlin

Dancers of the state opera ballet perform at the Opera Ball in Vienna

Leonhard Foeger/Reuters

Dancers of the State Opera Ballet perform at the Opera Ball in Vienna on Thursday

Gorillas with rugby balls

Ben Birchall/PA Wire

Komale, a Western Lowland Gorilla, inspects a rugby ball that has been placed into the enclosure at Bristol Zoo as part of its enrichment programme.