[填空题]
Calculate the bond lengt x9o*)41j 5cit xota qxwywt4q0zp, .mh for the NaCl mo erni-ypg j9 w,7urr0my*-eb*/ s2 dsclecule given that three successive wavelengths for r n7dy,u j9 iw-e*rsp-by ec20*sm rrg/otational transitions are 23.1 mm, 11.6 mm, and 7.71 mm. $r = $ $\times 10^{-10}\ \text{m}$
