问题
选择题
______, the conference began.
A．The candidates having taken their seats
B．The candidates had taken their seats
C．Taken their seats
D．Taking their seats
答案
答案：A
题目分析：考查独立主格结构。the conference不是take their seats的逻辑主语，排除C、D；当非谓语的主语跟主句主语不一致时，要带上自己的逻辑主语，B项不是非谓语动词短语，排除B。故选A。