— Excuse me,what impressed you most in his report?

— Well,the most important part,I think,lies in the words to bring about an ________ of the conditions of the working men and women．

1. A.
   improvement
2. B.
   advance
3. C.
   increase
4. D.
   achievement

---Excuse me, what impressed you most in his report?

---Well, the most important part, I think, lies in the words to bring about an _______ of the conditions of the working men and women.

A. achievement         B. advance          C. increase                        D. improvement