18. ----- Has Mary finished writing her article ?

    ----- No, and it _____ before class was over.

       A. should be finished                   B. should finish

       C. should have finished             D. ought to have been finished

 ----- Has Mary finished writing her article ?

    ----- No, and it _____ before class was over.

       A. should be finished                   B. should finish

       C. should have finished         D. ought to have been finished

— Has Mary finished writing her article?

— No, and it _____ before class was over.

A. should be finished           B. should finish

C. ought to have been finished    D. should have finished

-- Has Mary finished writing her article?

-- No, and it _____ before class was over.

A. should be finished 　　 B. should finish 　

C. should have finished 　 D. ought to have been finished

 — Has Mary finished writing her article?

— No, and it _____ before class was over.

A. should be finished           B. should finish

C. ought to have been finished    D. should have finished