托福阅读：如何看出“弦外之音”

托福阅读到底在考察什么？官方指南里面告诉我们是“在文章当中强烈暗示，但没有明确表明的”。一言以蔽之——弦外之音。要想知道什么是弦外之音的概念——比喻言外之意，即在话里间接透露，而不是明说出来的意思。

托福阅读为我们大张旗鼓的玩起了弦外之音这样的事情，这一点尤其在托福TPO里面体现得尤为明显。
我们当然还是拿真实例子说话，首先看一下托福真题TPO1里面的一段。
Groundwater is the word used to describe water that saturates the ground, filling all the available spaces. By far the most abundant type of groundwater is meteoric water; this is the groundwater that circulates as part of the water cycle. Ordinary meteoric water is water that has soaked into the ground from the surface, from precipitation (rain and snow) and from lakes and streams. There it remains, sometimes for long periods, before emerging at the surface again. At first thought it seems incredible that there can be enough space in the “solid” ground underfoot to hold all this water.
　　题目：
Which of the following can be inferred from paragraph 1 about the ground that we walk on?
A It cannot hold rainwater for long periods of time.
B It prevents most groundwater from circulating.
C It has the capacity to store large amounts of water.
D It absorbs most of the water it contains from rivers.

很显然原文At first thought it seems incredible that there can be enough space in the “solid” ground underfoot to hold all this water. 为我们提到很难想象，在如此“坚实”的地下，会有足够的空间来盛如此之多的水，这里就很隐晦的告诉我们其实地下并不“坚实”，而是还有很多的空间，来盛放 groundwater，因此我们得到的正确答案就是C选项，也就是原来我们行走的这片土地之下还有足够的能力来承载如此之多的水。
很显然，这里也是很隐晦的告诉我们地下空间其实是很大的。下面这道题也是一样。

The same thing happens to this day, though on a smaller scale, wherever a sediment-laden river or stream emerges from a mountain valley onto relatively flat land, dropping its load as the current slows: the water usually spreads out fanwise, depositing the sediment in the form of a smooth, fan-shaped slope. Sediments are also dropped where a river slows on entering a lake or the sea, the deposited sediments are on a lake floor or the seafloor at first, but will be located inland at some future date, when the sea level falls or the land rises; such beds are sometimes thousands of meters thick.
　　All of the following are mentioned in paragraph 3 as places that sediment-laden rivers can deposit their sediments EXCEPT
A A mountain valley
B Flat land
C A lake floor
D The seafloor

本题问的是到底哪里没有沉积呢？
dropping its load as the current slows: the water usually spreads out fanwise, depositing the sediment in the form of a smooth, fan-shaped slope. 告诉我们，只有在流速缓慢的地点才会沉积。但是他不直接告诉我们具体在什么地点，而是让我们去用逻辑推理。
因此当我们寻找的时候，发现Flat land“平缓之地”毫无疑问是流速缓慢的，这样的地方不会沉积，然后再告诉我们a river slows on entering a lake or the sea，湖和海洋，也是流速缓慢的地点，自然也不会沉积。那么唯一会沉积的地方也就只有上游mountain valley才会沉积，因为河流流经的地点分别是from a mountain valley onto relatively flat land，以及a river slows on entering a lake or the sea。
自然当我们排出了Flat land、a lake以及the sea之后，也就只可能剩下mountain valley了。
这就是托福阅读的特点，也就是不直接告诉我们答案，而是让我们在充分理解句意的情况下自己infer出答案。高！实在是高！