It was some time _______ we realized the truth.
A. when B. until C. since D. before
It was some time _______ we realized the truth.
A. when B. until C. since D. before
D
解析：此题考查句型惯用法。“It is (was)(not)一段时间+before ”“很长一段时间才；不久就……”等。另，此题许多学生易错选B. until但until前往往用实义动词，如：He had been waiting until I came back.. C项句型结构应是It is +一段时间+since（从句谓语一般过去时）或it was +一段时间+since（句中谓语过去完成时）故上句用since时态不对。所以答案是D。