It’s hard problem for the twins that of them can work it out.
A. so; neither
B. such a; neither
C. so a; neither
D. such a; none
网友回答
A. so; neither
(答案→)B. such a; neither
C. so a; neither
D. such a; none
解析：表示如此…以至于…有两种句式结构so…that…和so…that…,so后跟形容词或副词，而such后跟名词，根据题意problem是可数名词单数故用such a;有因neither表示两者都不…因此选B.