单选题
The board of directors have already discussed the subject ______ in the previous meetings and they will handle it in all its aspects.
【正确答案】
B
【答案解析】[解析] 四个选项的意思分别是at length详细地；in place准备妥当；on end连续地，不断地；off and on时断时续地。句意是，在前几次会议上，董事会已经详细地讨论了这个话题，并将全方位地进行处理。所以正确答案是B选项，如He talked at length about his work．(他详细地谈了他的工作)。