单词学习：accumulation 名词
accumulation
/əˌkjuːmjəˈleɪʃn/
积累，积聚；堆积物
The accumulation of teaching materials in Mr. Gu's office is a testament to his years of dedication.
顾老师办公室里教学资料的积累，是他多年奉献的证明。
单词卡片
卡片已就绪
