题目

 It’s _________ hard problem for the twins that ________ of them can work it out .  A. so, neither     B. such a, none     C. so a, neither     D. such a, neither 答案： D左手有2颗豆子，右手有5颗豆子，求两只手里总的豆子数，应列式为（ ）。A.2+2B.3+5C.2+5