【正确答案】:
FUNCTIONAL WORDS DO NOT HAVE NOTIONS OF THEIR OWN AND THEIR MAIN FUNCTION IS TO EXPRESS THE RELATION BETWEEN NOTIONS, WORDS ETC. 
【题目解析】:功能词本身没有概念,其主要功能是表达概念、词等之间的关系。
FUNCTIONAL WORDS DO NOT HAVE NOTIONS OF THEIR OWN AND THEIR MAIN FUNCTION IS TO EXPRESS THE RELATION BETWEEN NOTIONS, WORDS ETC.