It was some time I realized the fact that I had been cheated by the salesman.A. untilB. b

问题补充：

It was some time I realized the fact that I had been cheated by the salesman.

A. until

B. before

C. unless

D. since

答案：

A. until

(答案→)B. before

C. unless

D. since

解析：连词辨析。A直到…才；B在…前；C除非，如果…不；D自从；固定句式： It be 一段时间 before…一段时间以后某事才发生；如果before后面使用一般现在时，前面的主语使用将来时；如果before后面使用一般过去时，前面也使用一般过去时；句意：一段时间以后我才意识到我被这个销售员给欺骗了。故B正确。