reservoir
noun [ C ] uk/ˈrez.ə.vwɑːr/ us/ˈrez.ɚ.vwɑːr/
水库;蓄水池
a place for storing liquid, especially a natural or artificial lake providing water for a city or other area
储备;储藏;宝库
a large supply of something
The universities constitute a reservoir of expert knowledge. 大学是专业知识的宝库。