题目

A language never stands still .It is always changing and developing. These changes are rapid in primitive（原始的） societies, but slow in advanced ones, because the invention of printing and the spread of education have fixed a traditional usage. The only important change that English has undergone（遭受） since the 16th century is a large increase in its vocabulary. It is interesting to trace the different ways in which new words are invented. Let us take just two English words and see how they were made: sandwich and television.    Sandwich, is now no longer an entirely 两数的差是被减数的34，减数与差的比是______．