请求大家帮帮忙。。。一个阅读障碍。。。

这段话其实是逻辑CR中的一道题，不过我拿到阅读区来问问大家～～真心求教～～这种类似的障碍在阅读里也会经常碰到～～～～～

题目是这样的

14. Among the more effective kinds of publicity that publishers can get for a new book is to have excerpts of it published in a high-circulation magazine soonbefore the book is published. The benefits of such excerption include not only a sure increase in salesbut also a fee paid by the magazine to the book's publisher.Which of the following conclusions is best supportedby the information above?

(A) The number of people for whom seeing an excerpt of a book in a magazine provides an adequate substitute for reading the whole book is smaller than the number for whomthe excerpt stimulates a desire to read the book.

(B) Because the financial advantage of excerpting anew book in a magazine usually accrues tothe book's publisher, magazine editors areunwilling to publish excerpts from new books.
(C) In calculating the total number of copies that a book   has sold, publishers include sales of copies of   magazines that featured an excerpt of the book.
(D) The effectiveness of having excerpts of a bookpublished in a magazine, measured in termsof increased sales of a book, is proportionalto the circulation of the magazine in whichthe excerpts are published.
(E) Books that are suitable for excerpting in high-circulation magazines sell more copies thanbooks that are not suitable for excerpting.
正确答案A。

不用分析逻辑，其实如果有人给我翻译一下，它表达的是“读完摘录的人中, 更想买此书的人数要大于看了摘录就不想买此书的人”。给我翻译以后我就觉得很容易了。但是A选项这么写：provides an adequate substitute for reading the whole book is smaller than 。。。我就看不懂了。。Provides an adequate substitute,为什么就表示不看这种书呢。。？请问大家是怎么读懂的呢。。？我阅读的时候就经常会碰到这种类似的问题：关键的地方遇到一些我看不懂的表达，请问大家是怎么解决这个问题的呢？？？是要靠慢慢积累的吗？？？总感觉积累不完呀！！请求达人解答～～