893＋49的简便算法是请选择ABC.l6s+{,o'`6]0e9}7S;G1T4m2@
A.（893＋7）＋429}7S;G1T4m2@
B.（893＋50）＋19}7S;G1T4m2@
C.900＋49＋79}7S;G1T4m2@