以一道題目為例：
While researching a topic, a student has taken the following notes:
· The Million Song Dataset (MSD) includes main audio features and descriptive tags for popular songs.
· Audio features include acoustic traits such as loudness and pitch intervals.
· Many algorithms use these audio features to predict a new song's popularity.
· These algorithms may fail to accurately identify main audio features of a song with varying acoustic traits.
· Algorithms based on descriptive tags that describe fixed traits such as genre are more reliable predictors of song popularity.
The student wants to explain a
disadvantage of relying on audio features to predict a song's popularity. Which choice most effectively uses relevant information from the notes to accomplish this goal?
disadvantage
A. Many popularity-predicting algorithms are based on a song's audio features, such as loudness and pitch intervals.
B. Algorithms based on audio features may misidentify the main features of a song with varying acoustic traits, making such algorithms less reliable predictors of popularity than those based on fixed traits.
C. Audio features describe acoustic traits such as pitch intervals, which may vary within a song, whereas descriptive tags describe fixed traits such as genre, which are reliable predictors of popularity.
D. The MSD's descriptive tags are reliable predictors of a song's popularity, as the traits they describe are fixed.
題目要求選出一個句子，能夠最好地描述依賴聲音特征做預(yù)測的劣勢，參考材料是上方的5句話。
我們在訓(xùn)練的時候，會要求學(xué)生把選項先擋上，先思考這樣一個問題：“如果你想研究某個對象的劣勢，你面前放了很多篇文獻(xiàn)，你要一個字一個字讀嗎？”
以及另一個問題：“當(dāng)你把所有的劣勢全部整理好以后，應(yīng)該如何措辭，才能讓讀者方便理解？”從文法上來看，每句話的重點在這個句子的主干中，如果是表示評價或者后續(xù)影響的部分，可能放在逗號ing或者放在逗號which里。
把這兩個問題想明白以后，按照流程操作就可以了。如果要找一個對象的劣勢，一定要去文章里面找到否定或者負(fù)面的評價。在材料的五句話中，有一句話就有否定：These algorithms may fail to accurately identify main audio features of a song with varying acoustic traits. 這句話中的fail to表示沒能夠做成一件事。
學(xué)生在做SAT語文題的時候，除了要把句子的大意說出來，還要額外做一件事：把每個句子的功能總結(jié)出來。作者寫這句話是為了什么？引入背景？陳述現(xiàn)象？作出解釋？提出觀點？提出別人的觀點？評價一件事？等等。
先來看閱讀材料：
The Million Song Dataset (MSD) includes main audio features and descriptive tags for popular songs.
這句話的大意是：MSD包含了主要的流行歌曲的音頻特征和標(biāo)簽。
這句話的功能是：描述MSD的內(nèi)容。
· Audio features include acoustic traits such as loudness and pitch intervals.
這句話的大意是：音頻特征包括聲音特征，比如響度和音程。
這句話的功能是：描述audio feature的內(nèi)容。
· Many algorithms use these audio features to predict a new song's popularity.
這句話的大意是：很多算法用這些音頻特征預(yù)測一首新歌會不會火。
這句話的功能是：介紹一個算法的功能。
· These algorithms may fail to accurately identify main audio features of a song with varying acoustic traits.
這句話的大意是：如果一首歌有很多聲音特性的話，這些算法沒法準(zhǔn)確地識別一首歌的主要音頻特征。
這句話的功能是：描述某個算法的問題。
· Algorithms based on descriptive tags that describe fixed traits such as genre are more reliable predictors of song popularity.
這句話的大意是：如果算法基于像基因這樣描述固定特性的標(biāo)簽的話，那么這些算法就能夠更靠譜地預(yù)測一首歌能不能火。
這句話的功能是：算法靠譜的條件。
我們看一下幾個選項的大意和功能：
A選項：
Many popularity-predicting algorithms are based on a song's audio features, such as loudness and pitch intervals.
這句話的大意是：很多預(yù)測是否會火的算法是基于一首歌的音頻特征的，比如這首歌的音量和音程。
功能：描述某個算法的依據(jù)，不涉及評價和負(fù)面描述。
B選項：
Algorithms based on audio features may misidentify the main features of a song with varying acoustic traits, making such algorithms less reliable predictors of popularity than those based on fixed traits.
這句話的大意是：基于音頻特征的算法可能會錯誤地識別某些歌曲的主要特征，這些歌曲有很多的音頻特征。這樣一來，這種算法跟基于固定特征的算法相比，在預(yù)測歌曲是否會流行這方面，就不那么靠譜了。
這句話的功能是：指出某種算法的錯誤，并對該算法評價。
C選項：
Audio features describe acoustic traits such as pitch intervals, which may vary within a song, whereas descriptive tags describe fixed traits such as genre, which are reliable predictors of popularity.
這句話的大意是：音頻特征描述的是聲音的特性，比如音程，它在一首歌內(nèi)會發(fā)生變化，而描述性標(biāo)簽描述的是固定的特征，比如體裁，它可以很靠譜地預(yù)測一首歌會不會火。
這句話的功能是：兩種對象的內(nèi)容作比較。
D選項：
The MSD's descriptive tags are reliable predictors of a song's popularity, as the traits they describe are fixed.
這句話的大意是：MSD的描述性標(biāo)簽?zāi)軌蚝芸孔V地預(yù)測一首歌能不能火，因為這些標(biāo)簽所描述的特征是固定的。
這句話的功能是：對標(biāo)簽進(jìn)行正面評價，并給出解釋。
四個選項中，光看內(nèi)容，ABCD都或多或少有道理，但是真正能夠回應(yīng)題目要求的，出現(xiàn)了負(fù)面評價的只有B選項，它就是正確答案。
其實如果我們仔細(xì)研究SAT的考題就不難發(fā)現(xiàn)，無論是閱讀還是語法，出題人本質(zhì)想考察的并不是考生的英語能力，而是學(xué)術(shù)能力。這也是為什么那么多地區(qū)認(rèn)可SAT考試的根本原因。
