Question

Tom ought to ________ me your secret, but he meant no harm.

1. A.
   have told
2. B.
   tell
3. C.
   be telling
4. D.
   having told

Answer 1

A
【巧解导析】ought to do用来说现在之事；ought to have done用来说过去之事．根据句中meant可知应用过去时．ought not to have done表示“过去本不必做但实际上却做了”；ought to have done则表示“过去应做而实际却未做”．