（2） 上下文線索

    利用上下文線索猜測詞義的方法很多，但其核心是尋找與該生僻詞相關的上下文意義線索，這些線索主要可歸納為以下幾種：

    ①同義定義為了便于讀者理解作者本義，作者有時會對文中的生僻詞或專業(yè)性較強的詞直接給出定義。在下定義時，作者常使用一些信號詞，如：is/are(called)，means，can be defined as，refer to，is/are known as，signify等，例：Food fallacies refer to beliefs about food that are not true.

或標點符號，如——，()等，例：Multiplexing ——transmitting independent signals at the same time in the same channel——increases the efficiency of radio channels.

有時，作者用同位語形式或連詞or給出定義，例：

Nerve cells evidently first appeared in coelenterates, “hollow��gutted” organisms like hydra and the sea anemone.

Intelligent behavior remained impossible until the appearance of relatively big，complex types of brain——the types we find among the vertebrates，or backboned animals.

    ②近義復述同一短文中上下毗鄰的句子通常有互釋作用，我們可以從上下文的復述中獲取與某一單詞相關的信息來猜度詞義。例：

Mr. and Mrs. Firth had a long courtship. They dated for nine years before they got married.

Although he often had the opportunity，Mr. Tritt never stole money from a customer. This would have endangered his position at the bank，and he did not want to jeopardize his future.

    ③反義對照在表示對照的上下文中，常包含有意義相反的詞語或概念，這些意義相反的概念可以互為線索，幫助我們猜度詞義。常有以下一些信號詞：although，but，however，though，whereas，while，yet，on the contrary，on the other hand等。

例：Chimpanzees(猩猩) in the wild use simple objects as tools，but in laboratory situations they can use more sophisticated items. Most dentists-offices are drab places，while Emilio’s new office is a bright，cheerful place.

    ④搭配集合利用詞與詞的搭配或該詞所出現(xiàn)的語境，我們也能推知詞義的大概輪廓。例：

People gathered to look. Three fine streams of hot water sprouted from holes in the jacket(套，殼) of the radiator.

A man is watering his lawn just as an attractive，well dressed girl walked by. As he ogles her，he accidentally turns the hose on his ugly，dowdy wife.

    ⑤比較舉例上下文中的比較和舉例，能揭示比較物或列舉物之間的共性，我們可根據(jù)這些共性來推知有關詞語的意思。例：

The consequences of epochal events such as wars and great scientific discoveries are not confined to a small geographical area.

Doctors believe that smoking cigarettes is detrimental to your health. They also regard drinking as harmful.

    ⑥因果時間因與果、時間的先與后都是事物發(fā)展變化過程中的必然關系，在利用上下文推測詞義時，這些關系也至關重要。例：

Robert is considered peremptory administrator because he makes decisions without seeking the opinions of others.

When Mark was in pedantic mood，he assumed the manner of a famous professor and gave long lectures on boring, insignificant topics.

    ⑦常識包括我們的生活經歷、經驗常識以及自己專業(yè)方面的知識，在閱讀到與自己專業(yè)相近的文章時，我們都會感到相對容易，這正是我們的專業(yè)知識在幫我們理解。例：

An apple falls down instead of up because of gravity.

An atomic clock is so precise that it can be used to check the accuracy of predictions based on Einstein’s relativity theories.