QUES: acceptable
ANS: All who come will have a good time.

QUES: acceptable
ANS: The teacher set us a problem the answer to which we can find in the textbook.

QUES: unacceptable
ANS: Tracy has become a republican and of the opinion that we must place nuclear weapons in Europe.

QUES: unacceptable
ANS:
The kennel in which Mary made and Fido sleeps has been stolen.