19. There were two boys in the lab, ______did the experiment successfully.

  A. the clever of whom  

B. the cleverer or whom

  C. the clever of them

  D. the more clever of them

There were two boys in the lab,_____did the experiment successfully.

  A. the clever of whom      B. the cleverer or whom

  C. the clever of them       D. the more clever of them

There were two boys in the lab, ________ did the experiment successfully.

 A. the clever of whom   B. the cleverer or whom

 C. the clever of them   D. the more clever of them

 There were two boys in the lab,___________did the experiment successfully.

  A. the clever of whom        B. the cleverer or whom

  C. the clever of them         D. the more clever of them

There were two boys in the lab,       did the experiment successfully.

  A. the clever of whom  

B. the cleverer or whom

  C. the clever of them

  D. the more clever of them