as an annual ecological awareness event on April 22, from 1970; the idea for it and the name date from 1969.
updated on October 13, 2020
英语词源词典收录了45867条英语词源词条，基本涵盖了全部常用英语词汇的起源、历史，是研究英语词汇或通过词源学英语的必备工具。