【正确答案】：
（1）DIFFERENCE IN DENOTATION: SYNONYMS MAY DIFFER IN THE RANGE AND INTENSITY OF MEANING. SOME WORDS HAVE A WIDER RANGE OF MEANING THAN OTHERS. FOR EXAMPLE, TIMID AND TIMOROUS ARE SYNONYMOUS, BUT THE FORMER IS APPLIED TO BOTH THE STATE OF MIND IN WHICH A PERSON MAY HAPPEN TO BE AT THE MOMENT, AND TO HABITUAL DISPOSITION, AND THE LATTER ONLY TO THE DISPOSITION. 
（2）DIFFERENCE IN CONNOTATION: SOME WORDS SHARE THE SAME DENOTATION BUT DIFFER IN THEIR STYLISTIC APPROPRIATENESS. FOR EXAMPLE, THE WORDS BORROWED FROM FRENCH AND LATIN ARE GENERALLY MORE FORMAL THAN WORDS; ANSWER/RESPOND, HOMELY/DOMESTIC, FLESHY/CARNAL. IN EACH PAIR, THE FIRST TERM IS NATIVE AND NOT STYLE SPECIFIC WHEREAS THE SECOND TERM IS BORROWED EITHER FROM FRENCH OR LATIN AND IS MORE FORMAL. 
（3）DIFFERENCE IN APPLICATION: MANY WORDS ARE SYNONYMOUS IN MEANING BUT DIFFERENT IN USAGE IN SIMPLE TERMS.  THEY FORM DIFFERENT COLLOCATIONS AND FIT INTO DIFFERENT SENTENCES PATTERNS. FOR EXAMPLE, ALLOW AND LET ARE SYNONYMS, BUT WE ALLOW SB. TO DO STH. AND LET SB. DO STH.
【题目解析】：（1）外延上的差异：同义词在意义的范围和强度上可能有所不同。有些词的含义比其他词更广泛。例如，timid（胆怯）和timorous（胆怯）是同义词，但前者适用于一个人可能此时的精神状态，也适用于习惯性性格，后者仅适用于性格。（2）内涵上的差异：有些词具有相同的外延，但在文体适用性上有所不同。例如，从法语和拉丁语借来的单词通常比一般的单词更正式；回答/回应，家庭/家庭，肉欲/肉欲。在每一对中，第一个术语是本地的，而不是特定于样式的，而第二个术语是从法语或拉丁语中借用的，并且更正式。（3）应用上的差异：许多词在意义上是同义词，但在用法上不同。它们形成不同的搭配，适合不同的句型。例如，allow和let是同义词，两个短语是允许/让某人做某事。