试题题干
Complete the following statements with proper words or expressions according to the course book.
Vocabulary is the most unstable element of a language as it is undergoing constant changes both in form and 
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参考答案
试题解析
Vocabulary is the most unstable element of a language as it is undergoing constant changes both in form and content. 词汇是语言中最不稳定的一种要素，因为它在形式和内容上都在不断变化。