At first balls were made of grass or leaves held together by vines.

起初，球是用藤条把草或树叶捆在一起做成的。

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The Eskimos played soccer on ice and used balls filled with caribou hair and grass.

爱斯基摩人在冰上踢球，他们用的是驯鹿的毛发和草填充成的球。

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Shore, a bunch of children noodle plate light shoes, grass, small balls wrinkled pants coat bunched up into the flowers.

岸边，一堆光鞋板儿横七竖八，草丛里，一团团小裤褂揉成皱花儿。

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Some soccer teams wet the field before a match to make the ball roll faster, while baseball teams grow out grass to slow ground balls.

WSJ: In Golf Rivalry, Important Equipment Includes a Mower

White balls discoloured by the grass are difficult for fielders and batsmen to see in certain light conditions.

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"He used to (serve and volley), but I think the conditions of the grass have changed so much -- the balls are probably heavier, the courts are much, much slower, so there is far less serve and volley, " Henman told CNN.

CNN: Death of a tennis art: Is this the end for serve and volley?