His essay, ____many times,was brief and to the point,and therefore won the first prize in the writing competition.?

     A.polishing up           

     B.having polished up?

     C.to be polished up

     D.having been polished up?

His essay, ______ many times, was brief and to the point and therefore won the first prize in the writing competition.

  A. polishing up                                         B. having polished up   

  C. to be polished up                                   D. having been polished up

His essay, ____many times,was brief and to the point,and therefore won the first prize in the writing competition.

1. A.
   polishing up
2. B.
   having polished up
3. C.
   to be polished up
4. D.
   having been polished up

　 His essay, ______ many times, was brief and to the point and therefore won the first prize in the writing competition.

　 A. polishing up　　　　　　　　　　 B. having polished up　

　 C. to be polished up　　　　　　　 D. having been polished up