Question

9. I received his mother's telephone call at eleven. Only then        that he was badly hurt in an accident yesterday (know)

我十一点接到了他妈妈的电话。直到那时我才知道他昨天在车祸中严重受伤。

Answer 1

9. did I know only后跟状语且位于句首时，句子用部分倒装结构。