instruction: Is the next sentence syntactically and semantically acceptable?

He cannot have been working.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Pat was believed to have been examined by the dentist.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Which girl ate the cake?

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

That the police wanted him worried Johns but it didn't worry the boy who Mary knew.

response:
acceptable