单选题 --Mark broke his leg when he was playing football.
-- ______ was that?
  • [A] Since when
  • [B] Since when ago
  • [C] How long
  • [D] How long ago


【正确答案】 D
【答案解析】[考点] 时间副词的用法
[解析] A项表示“自从什么时候……”，用于表示完成时态；B项搭配错误；C项表示时间延续，“多久”，break为短暂性动词，故排除。