答案這一端沒封住
開口如果在「答案」那一頭，就沒有人先決定好答案該長什麼樣子，也沒有規定要怎麼做。
adjective · B2
Having no fixed answer and no fixed rules about how it must be done, so the people doing it decide how far to take it and which way to go.
開放式的
核心畫面
One way to hold this word: picture a tube with one end left open. Something has been started, but nobody has put a cap on the far end. Whatever comes out of that opening is allowed to keep coming — as far as it wants, for as long as it wants. Every use of open-ended is about which end was left uncapped.
open-ended 可以想成一根管子，只有一端封起來，另一端就那樣開著。事情有起點，但沒有人先去把遠的那一頭封住。…更多收起
open-ended 可以想成一根管子，只有一端封起來，另一端就那樣開著。事情有起點，但沒有人先去把遠的那一頭封住。所以東西可以一直從那個開口跑出來：要跑多遠、跑到什麼時候，都還沒被決定。這個字的每一種用法，差別只在「開著的是哪一端」。Two branches
時間這一端沒封住
同一個開口，換成開在「時間」那一頭：開始的日期有了，結束的日期還空著。
adjective · B2
Arranged with no set finishing date, so it carries on until someone decides to bring it to an end.
沒有期限的