Riderless
a. 沒人騎的, 無主的（馬）
??? 情景例句
We'll call in a couple of days.
我們兩三天后打電話。
You haven't sold your product in our country so far, have you?
到目前為止，你們的產品尚未在我們國家銷售，是嗎？
The system has worked so well, that it has been adopted in other countries too.
由于這種制度行之有效，已被其他國家采納。