【题目】A full preparation before Beijing finally won the bid for hosting the 2022 Winter Olympic Games.
A. has been made B. had been made
C. would be made D. is made
在线课程【答案】B
【解析】句意为：北京在最终赢得2022年冬奥会主办权之前已经做了充分的准备。该句中“before Beijing finally won the bid”使用了一般过去时态，而做准备发生在won这个动作之前，因此使用过去完成时态。