【正确答案】：
（1）MOTIVATION ACCOUNTS FOR THE CONNECTION BETWEEN THE LINGUISTCI SYMBOL AND ITS MEANING.
（2）SEMANTIC MOTIVATION, ONE OF THE FOUR MAJOR TYPES OF MOTIVATION, EXPLAINS THE CONNECTION BETWEEN THE LITERAL SENSE ANS FIGURATIVE SENSE OF THE WORD.
（3）IN THIS SENTENCE, ‘PEN’ REMINDS ONE OF THE TOOL TO WRITE WITH, THUS SUGGECTING WRITING; 'SWORD' REMINDS ONE OF THE WEAPON TO FIGHT WITH, THUS SUGGESTING WAR. 
【题目解析】：（1）理据解释了语言符号与其意义之间的联系。（2）语义理据是四种主要的理据之一，它解释了单词的字面意义和比喻意义之间的联系。（3）在这句话中，“笔”使人想起书写的工具，从而联想到书写；“剑”使人想起与之战斗的武器，从而联想到战争。