Question

Not until he took off his dark glasses ___________ he was a famous film star

1. A.
   had I found
2. B.
   did I find
3. C.
   I found
4. D.
   found I

Answer 1

B
考查时态及主谓倒装，句意：直到他摘下他的墨镜时，我才发现他是一个著名的影星。Not until谓语句首时，主语采用部分倒装，助动词提前。结合语境可知主语描述的是过去某时的动作，助动词用一般过去时态。选B。