7. The boy is able to solve the difficult math problem ____ he is only ten years old.(A) unless (B)

問題詳情

7. The boy is able to solve the difficult math problem ____ he is only ten years old.
(A) unless
(B) even though
(C)because
(D)since)

答案：B
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)