[填空题]
The gauge pressure in in1 :dxevoeifjo (.9 xmd65 0da hemk6 qf8no 37e mtk58calium gas cylinder is initially 28 atm. After many balloons have been blow876eamk5no8mktfq 3 c n up, the gauge pressure has decreased to 5 atm. What fraction of the original gas remains in the cylinder?