Complete the following statements with proper words or expressions according to the course book.The ( ) of an expression is not a thing, so it is difficult to say what sort of identity it is. For example, and, if, yes don't refer to anything in the world, but all have meanings.
【正确答案】：SENSE
【题目解析】：表达的意义不是一件具体的事，所以很难说它是哪一种特性。例如，and（而且），if（如果）和yes（肯定回答）不是指世界上的任何东西，但都有意义。
