91色情片

Soldiers may no longer play football in no-man鈥檚-land, but that hasn鈥檛
stopped Britain鈥檚 Defence Evaluation and Research Agency developing a smart
football. The ball tells you when it鈥檚 inflated to the correct pressure (GB
2353864). It has a patch in its surface in which two films are separated by an
opaque gel. The top film is transparent, while the lower one is embossed with a
diamond and a cross, with the cross standing more proud than the diamond. When
the ball is under-inflated, the gel spreads thickly and neither cross nor
diamond is visible. At the correct pressure, the cross alone touches the top
film, but over-inflation squeezes the films so tightly that both shapes are
visible.