Obligational
a. obligation（义务, 责任）的变形
✅ 同义词
🔴 反义词
🗣️ 情景例句
With a family in the Bronx.
住在Bronx区的一个家庭 。
Many sands will sink a ship.
积沙沈船。
it was not long before its use as the uniquely recognizable broadcasting frequency for interstellar communication was suggested.
提出把它作为星际间唯一可辨认的广播频率就为期不远了。