duty / exercise, assignment (set for homework)

must, to have to, should (as a requirement) / must, to do or have with certainty / to owe (money, obligation and etc) / (even) though it be necessary (+ infinitive) / to have a duty to

test, examination

duty of remembrance, duty never to forget, obligation to remember

duty calls (I gotta go, I have something to do)

(law) duty of care (legal obligation imposed on an individual requiring that they adhere to a standard of reasonable care while performing any acts that could foreseeably harm others)

written test

feeling of accomplishment, feeling of having accomplished one's duty, satisfaction of having seen something through

to owe (someone) one [+ à (object)]

to make it one's duty to do something, to make a point of doing something, to commit to do something, to set out to do something