問題詳情

29. Flooding in this area _____ to happen far more often a decade ago than it does today, but it has changed.
(A) has been used
(B)had used
(C) has used
(D) used

參考答案

答案：D
難度：困難0.333333
統計：A(10),B(12),C(2),D(13),E(0)