They _____ of the terrible situation in Thailand, otherwise they wouldn't have gone there for sightseeing.

1. A.
   wouldn't hear
2. B.
   didn't hear
3. C.
   haven't heard
4. D.
   don't hear

They _____ of the terrible situation in Thailand, otherwise they wouldn't have gone there for sightseeing.

A．wouldn't hear        B．didn't hear      C．haven't heard         D．don't hear

They _____ of the terrible situation in Thailand, otherwise they wouldn't have gone there for sightseeing.

A．wouldn't hear           B．didn't hear          C．haven't heard      D．don't hear

They ________ of the terrible situation in Thailand, otherwise they wouldn't have gone there for sightseeing.

A. wouldn't hear　 　B. didn't hear　 C. haven't heard　 D. don't hear

They _____ of the terrible situation in Thailand, otherwise they wouldn't have gone there for sightseeing.