The most vigorous and on-going change in the historical developm

The most vigorous and on-going change in the historical development of a language is the change in its v______.
【正确答案】：vocabulary(P141)解析:在语言历史的变迁中最富生命力而且从来没有停止过的变化恐怕要属语言词汇方面的变化了。