从下面提供的答案中选出入下列英文语句中______内的正确答案。 It is traditional when dealing with languages of all sorts to try to separate concerns with (1) , the subject of syntax, from concerns with (2) , the field of semantics. Consider the simple "language" of binary numerals. Some examples of binary numerals are 1 101 101 11001 101111 A communication in this language evidently consists of afinite sequence of characters “0”、“1". This is just syntax however, and says (3) about what such a communication is intended to mean. Numbers are" (4) " mathematical concepts, whereas the digit strings that appear on paper are numerals, that is to say, (5) representations or descriptions of numbers.