[填空题]
Estimate the number of air molecules in a room of length 6.5 m, wismgl a7yh21 r-dth 3.1 q odp(mcjdrjlzc6c 2:c9x; ef, 0+f5 qt:h ;dom, and heipmz02dc ooed( + 5ft dj;r:c;lfj ccq ,6h9q:xght 2.5 m. Assume the temperature is 22$^{\circ} $C. How many moles does that correspond to? $\times10^{27 }$ molecules moles