Problem: Produce a sentence that would be considered grammatically acceptable

Answer: All the students who the papers which they submitted were lousy I'm not going to allow to register next term.

Problem: Produce a sentence that would be considered grammatically acceptable

Answer: This girl will buy bread and so will that one buy bread.

Problem: Produce a sentence that would be considered grammatically acceptable

Answer:
Everybody who is in Mary's semantics seminar is writing a paper on polarity items.