| 释义 |
keystone
UK ['ki:.stəʊn] US [-stoʊn] noun countable
STONE 石
■the middle stone in the top of an arch which has a special shape and holds all the other stones in position 拱顶石；塞缝石
UK ['ki:.stəʊn] US [-stoʊn] noun countable
IMPORTANT PART 基础
■the most important part of a plan, idea, etc. on which everything else depends （计划、想法等的）基础，主旨，基本原则 |