6.     Which
of the following best completes the passage below?

    

Established companies concentrate on
defending what they already have. Consequently, they tend not to be innovative
themselves and tend to underestimate the effects of the innovations of others.
The clearest example of this defensive strategy is the fact that______

    

(A) ballpoint
pens and soft-tip markers have eliminated the traditional market for fountain
pens, clearing the way for the marketing of fountain pens as luxury or prestige
items

    

(B) a highly
successful automobile was introduced by the same company that had earlier
introduced a model that had been a dismal failure

    

(C) a
once-successful manufacturer of slide rules reacted to the introduction of
electronic calculators by trying to make better slide rules

    

(D) one of the
first models of modern accounting machines, designed for use in the banking
industry, was purchased by a public library as well as by banks（C）

    

(E) the inventor of a commonly used
anesthetic did not intend the product to be used by dentists, who currently
account for almost the entire market for that drug

答案 c