【正确答案】：
CONTEXT PALYS A VITAL ROLE IN THE FOLLOWING THREE ASPECTS. 
1)ELIMINATION OF AMBIGUITY. WHEN A WORD WITH MUTIPLE MEANINGS IS USED IN INADEQUATE CONTEXT, IT CREATES AMBIGUITY, E.G. "HE IS A HARD BUSINESSMAN." THE WORD HARD IN THIS CONTEXT CAN MEAN BOTH ‘’HARDWORKING‘ AND ‘DIFFICULT’. THE CONTEXGT FAILS TO NARROW DOWN THE MEANING SO THAT IT IS DIFFICULT FOR THE READER TO DECIDE WHAT EXACTLY THE SPEAKER MEANS. 
2) INDICATION OF REFERENTS. ENGLISH HAS A LARGE NUMBER OF WORDS SUCH AS NOW/THEN, HERE/THERE, I/YOU, THIS/THAT, WHICH ARE OFTEN USED TO REFER DIRECTLY TO PEOPLE, TIME, PLACE, ETC. WITHOUT CLEAR CONTEXT, THE REFERENCE CAN BE VERY CONFUSING. FOR EXAMPLE, THE WORD NOW ALWAYS MEANS THE TIME OF SPEAKING, NATURALLY REFERRING TO A PAST TIME WHEN THE SPEECH TOOK PLACE IN THE PAST OR A PRESENT MOMENT IF THE PERSON IS SPEAKING. 
3)PROVISION OF CLUES FOR INFERRING WORD MEANING. CONTEXT MAY PROVE EXTREMELY VALUABLE IN GUESSING THE MEANINGS OF NEW WORDS. CONTEXT CLUES VARY A GREAT DEAL BUT CAN BE  SUMMED UP AS FOLLOWS: DEFINITION; EXPLANATION; EXAMPLE; SYNONYM; ANTONYMY, HYPONYMY; RELATIVE DETAILS; WORD STRUCTURE.
【题目解析】：语境在以下三个方面起着至关重要的作用。1）消除歧义。当一个词在不恰当的语境中使用时，它会产生歧义，例如“他是一个难对付的商人”。在这种语境中，“难对付”这个词既意味着“努力工作”，也意味着“困难”。Contexgt无法缩小词义范围，因此读者很难确定说话者的确切含义。2）限定所指。英语中有大量的单词，如“现在/那时”、“这里/那里”、“我/你”、“这个/那个”，这些单词经常被用来直接指代人、时间、地点等。如果没有清晰的上下文，所指可能会非常混乱。例如，“现在”这个词总是指说话的时间，自然地指的是过去演讲发生在过去的时间，或者是现在演讲的时间。3）提供推断词义的线索。在猜测新词的意思时，语境可能是非常有价值的。上下文线索变化很大，但可以概括为：定义；解释；示例；同义词；反义词，下义词；相关细节；词的结构。