Each sentence below has one or two blanks, each blank indicating that something has been omitted Beneath the sentence ate five, words or sets of words labeled A through E. Choose the word or set of words that, when inserted in the sentence, best fits the meaning of the sentence as a whole. 

Example: Medieval kingdoms did not become constitutional republics overnight; on the contrary, the change was ----. 

{A) unpopular (B) unexpected (C) advantageous (D) sufficient (E) gradual

The use of tools among chimpanzees is learned behavior: young chimpanzees become ---- by ---· others. 

(A) socialized .. overcoming

(B) dominant .. obeying

(C) vocal .. mimicking 

(D) adept .. imitating

(E) agile .. following