- It’s hard problem for the twins that of them can work it out.A. so; neitherB. such a;

问题补充：

- 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

答案：

A. so; neither

(答案→)B. such a; neither

C. so a; neither

D. such a; none

解析：such+a+adj+n[C]单数，根据前文内容the twin，neither of表示两者都不，故选B