He rolled the clay into a ball.

他把粘土揉成一个球。

youdao

Compress this clay into a small ball.

把这块粘土压缩成一个小球。

youdao

First hold the nail with the wide head by its shaft and push it head-first into the ball of clay.

首先将宽头钉的杆竖起，将其头朝下推入橡皮泥球。

youdao

A ball of clay is placed on a flat wheel device that turns quickly.

VOA: special.2009.09.09

People form containers by pressing a ball of clay into a given shape.

VOA: special.2009.09.09

On clay, the ball bounces much higher than on other surfaces, so players have to hit the ball at shoulder level.

BBC: Clay brings tension to surface

But on a high friction surface like clay, the ball will grip more and change the trajectory of the ball quite significantly.

BBC: SPORT | Tennis | Rules and Equipment | On the rebound

The reason: All four of the top American hopes possess serves and groundstrokes which are strong enough to be weapons on any surface, and the slow, high bounce on clay brings the ball into their hitting zone with sufficient time for them to set up their shots.

WSJ: Americans Produce Feats on Clay