instruction: Is the next sentence syntactically and semantically acceptable?

Harry thinks that Sally is innocent, although no one else thinks so.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

Only Churchill remembered giving the Blood, Sweat and Tears speech.

response: acceptable

instruction: Is the next sentence syntactically and semantically acceptable?

John was wondering to whom he was referring to.

response: unacceptable

instruction: Is the next sentence syntactically and semantically acceptable?

A woman hit a girl who was pregnant.

response:
acceptable