keystone

US /ˈkiˌston/

UK /'ki:stəʊn/

C2 高級
n.名詞楔石
The keystone contained the initials of the builder and year of erection

影片字幕

新年決心|克服困難 (NEW YEAR'S RESOLUTIONS | Overcome the Odds)

08:01新年決心|克服困難 (NEW YEAR'S RESOLUTIONS | Overcome the Odds)