树上有8只鸟,又飞来了4只,现在有几只?-v4\3_1R(m+|'_
算式:提示3M9j(m2b2y0f.U9B3J/}-v4\3_1R(m+|'_
答:现在有'A5w(]6}-q;r)@4w1Y0g(G2{只。-v4\3_1R(m+|'_