題目：
I _____able to tell you everything you want to know, if l _____what happened to him last night.
(A) were / knew
(B) were / had known
(C) would be / had known
(D) would be / knew
疑問：答案是c
想問為什麼d不行呢？不是與現在事實相反的假設嗎？謝謝～～