[填空题]
In an internal combusto4 u3/iit5 bv4y dp 4;*yhhmqdion engine, air at atmospheric pi j- wude odmau:.uu7s.y4o0/ ressure and a temperature of abou o myusu uu7idoe .-w:a0j4d./t 20$^{\circ} $C is compressed in the cylinder by a piston to $\frac{1}{9}$ of its original volume (compression ratio = 9.0). Estimate the temperature of the compressed air, assuming the pressure reaches 40 atm. $^{\circ} $ C