[填空题]
A neutron star consists o8do 8ee4y+bk+t8 scl rh18bpxf neutrons a ,rgx1(v );bnkz p:dsf(db;y bt approximately nuclear density. Estimate, for a 10-km-diamy vzbp ;(d1(,sg:x ;fkbdb)nreter neutron star,
(a) its mass number, A = $ \times 10^{55}$
(b) its mass (kg),m = $ \times 10^{29}\ \text{kg}$
(c) the acceleration of gravity at its surface. g = $ \times 10^{11}\ \text{m/s}^2$