请教lsatT5/S4/Q13

mzyzhu

Q13. The only way that bookstores can profitably sell books at below-market prices is to get the books at a discount from publishers. Unless bookstores generate a high sales volume, however, they cannot get discounts from publishers. To generate such volume, bookstores must either cater to mass tastes or have exclusive access to a large specialized market, such as medical market, or both.

13. Which one of the following can be properly inferred from the passage?

(A) If a bookstore receives discounts from publishers, it will profitably sell books at below-market prices.
(B) A bookstore that caters to mass tastes or has exclusive access to a large specialized market will have a high sales volume.
(C) A bookstore that profitably sells books at below-market prices gets discounts from publishers.
(D) A bookstore that does not sell books at below-market prices does not get discounts from publishers

the answer is C. can anyone explain why C is right answer and why A, B, and D is not?

我自己的解释是：
A, 将原文的必要条件get discount from the publisher变成了充分条件
B, 似乎也是将原文的必要条件变成充分条件。我感觉原文的语气有点像if bookstores want to generate high volume, bookstores must…
C, 我认为就是原文第一句话的改写。
D, 时原文第一句话的否命题，原命题成立否命题不一定成立。

不知我的理解是否正确？请指教

mike1999

同意！