| 摘要 |
<p>A device 1 comprises a body having a non-planar and uneven surface so that in use a ball thrown against the surface bounces off at unpredictable angles. The body may have a domed shape 2 bearing a plurality of indentations 4 and ridges 5. Alternatively, radial or circumferential ridges or rounded protrusions may be provided. The device may include a spike or pegs to assist in anchoring it to the ground. <IMAGE></p> |
