Though borrowing has been playing an active role in the ( ) of v

Though borrowing has been playing an active role in the ( ) of vocabulary as indicated, in modern times, however, vocabulary is largely enriched on an internal basis. 
【正确答案】：EXPANSION
【题目解析】：虽然借用在词汇扩展中发挥了积极作用，但在现代，词汇在很大程度上是内在的基础。