6.The problem is _____ even Helen’s professor cannot solve it.(A) too easy to that (B) so difficult

問題詳情

6.The problem is _____ even Helen’s professor cannot solve it.
(A) too easy to that
(B) so difficult that
(C) so crisp that
(D) so wonderful that

答案：B
難度：計算中-1
書單：沒有書單，新增