Used to express obligation, propriety, or expediency.

表义务、礼仪或权宜。

youdao

With the infinitive to express obligation or what is expected to happen.

与不定词连用，表示义务获预期发生某事。

youdao

The bishops were right to express their "moral obligation to speak up for those who have no voice".

主教们表达“为那些不能发声的人说话是一种道德义务”的观点是正确的。

youdao

And one of the wonderful things about democracy is that when the people are not happy, it is their right, obligation, and duty to express their unhappiness, much to the regret sometimes of incumbents.

WHITEHOUSE: Town Hall with Students in Mumbai