填空;F:o:V*?;S
6×3读作(J+f+h6X2Q*}([9E8Q/~.K乘以)U9@)g3q(D5v'`0Q*}，表示-E(I7w.@(J0I4n-n+i)k;a6l个2h*@6O6T4_3h:a+M-[6l连加。;F:o:V*?;S