what 从句可以看作是一个名词短语，同时，what又在句子中充当句子成分，因此它的用法比较活，有点弯弯绕绕的感觉，有时甚至让你理解不通。这里，我们举两个实例，他们的用法都很典型。
8-14
Personal trainers and fitness coaches are to the narcissistic 1980’s just [U][U]like a private fencing master and dancing teacher was [/U][/U]to an earlier time。
（A）
（B）as have been a private fncing master and dancing teacher
（C）what private fencing masters and dancing teachers were
（D）what private fencing masters and dancing teachers are
（E）just the same as private fencing masters and dancing teachers had been
题解：本题考到的是what的一种特殊用法，即：A1 is to A2 what A3 is to A4。为了便于理解，我们举一道TOEFL 试题来加深对此题的理解。TOEFL中曾有一选择题：
Color，line，mass，space and texture are to a painter_______ to an autor.
A: are what words
B: what are words
C: what words are
D: words are what
答案是：C。
本句可翻译为“色彩、线条、空间与画家的关系就如同语言和作家的关系一样”。what 从句的真正位置应在are 和to之间，做表语成分；而在what从句中，what这个词所做的成分同样是表语。还原即为words are what to an author。该TOEFL 填空题目与本题属同一结构。由此，我们可以确认答案在C、D之间；由于what从句中的时间状语是an earlier time，它提示我们时态应选过去式，选C。
8-15
His studies of ice-polished rocks in his Alpine homeland， far outside the range of presentday glaciers， led Louis Agassiz in 1837 to propose the concept of an age [U]in which great ice sheets had existed in now currently temperate areas。[/U]
（A）
（B）in which great ice sheets existed in what are now temperate areas
（C）when great ice sheets existed where there were areas now temperate
（D）when great ice sheets had existed in currently temperate areas
（E） when great ice sheets existed in now that are temperate
题解：本题涉及的是what的另一表达，即：假设原来某地没有名字，而现在叫做A地；那么，如果要表达“原来没有名字的这个地方”，就应该用what，即what is now known as A。这种表达既准确，又简洁。同理，本句应该选B。作者: princess 时间: 2002-10-20 11:59
