11. For democracy to survive, it is imperative that the average citizen be able to develop informed opinions about important policy issues. In today's society, this means that citizens must be able to develop informed opinions on many scientific subjects, from ecosystems to defense system. Yet, as scientific knowledge advances, the average citizen is increasingly unable to absorb enough information to develop informed opinions on many important issues.
Of the following, which one follows logically from the passage?
(A) Scientists have a duty to educate the public.
(B) The survival of democracy is threatened by the advance of scientific knowledge.
(C) Every citizen has a duty to and can become scientifically literate.
(D) The most effective democracy is one that is the most scientifically unsophisticated.
(E) Democracy will survive if there are at least some citizens who are capable of developing informed opinions on important scientific issues.
answer:B my choice:E
imperative = necessary . so citizens' ability to have informed opinion is the necessary condition for the survival of democracy. The line of reasoning is also same to: only if A, then B, if not A ( in the last sentence, the citizens' increasing inability to develop informed opinion as result of scientific advancement) then not B ( the democracy will not survive).
There is no clue in artcle to show you the fact in choice E.
To put it generally and concisely, in expression like this: if A, then B, A is the sufficient condition to B. For the expression: only if A, then b , or must A , in order to B, or A is necessary to B, A is the necessary condition to B. In sufficient condition scenario, from A you can deduct B. In a necessary condition scenario, from B you can deduct A. That is all. But i really suggest you to find some basic logic book to make clear all these concepts.
