字神帝國英語天地

Radio stations with radio data system (RDS) technology broadcast special program information that only radios with an RDS feature can receive. Between 1994 and 1996, the number of RDS radio stations in Verdland increased from 250 to 600. However, since the number of RDS-equipped radios in Verdland was about the same in 1996 as in 1994, the number of Verdlanders receiving the special program information probably did not increase significantly.

Which of the following is an assumption on which the argument depends?
A. Few if any of the RDS radio stations that began broadcasting in Verdland after 1994 broadcast to people with RDS-equipped radios living in areas not previously reached by RDS stations.
B. In 1996 most Verdlanders who lived within the listening area of an RDS station already had a radio equipped to receive RDS.
C. Equipping a radio station with RDS technology does not decrease the station's listening area.
D In 1996 Verdlanders who did not own radios equipped to receive RDS could not receive any programming from the RDS radio stations that began broadcasting in Verdland after 1994.
E. The RDS radio stations in Verdland in 1996 did not all offer the same type of programming.

如果馬上要參加GMAT考試，可直接看思路整理：
1：必須是某種特殊的收音機，才能收到特殊的廣播信號。
2：廣播電臺在增多。請注意，這已經發生重要資訊的變化。
3：但是，收音機的數量幾乎不變。
4：所以，能收到特殊信號的民眾數量，也不會顯著增多。

那這篇argument的核心論證就是：
只要radio數量不變，station增多也不會使得audience增多。換種說法，對於audience而言，radio比station更有決定性。

分析：文章的邏輯太片面強調radio與audience的一對一關聯性，給我們留下了置疑的餘地。

1：過去radio的使用沒有達到飽和，audience數量依然可能增多。

2：即使1的問題得到解決，那麼能聽到每台radio的audience還是可以增多。比如。94年只有家庭才購買特殊的radio，但到96年，學校和單位也開始配置這種radio。

正確答案：A，就是我們第1點分析的，不會存在有radio但收不到signal的局面。好比某些偏僻的革命老舊區域，即使送給孩子們iphone，他們也無法進入GMAT備考的公共帳號，因為各種沒信號。所以，station增多之後，還是會顯著改善這個問題。

干擾選項：D，內容其實和A的思路很相似，但與文章資訊“特別的信號給特別的收音機”發生矛盾，因此不必再重複假設一次。