人们有权利但是也有责任，这些责任并不是自愿的。

People had rights but also duties, and these duties were not voluntary.

youdao

除非参加者不是自愿的，在我看来，一切都是可以接受的。

Unless it is against the will of the participant, everything is acceptable, in my opinion.

youdao

托马斯·杰斐逊的宣言是在一名代笔的帮助下写的，那是一名叫做贝蒂美的有色人种女性，她不是自愿的。

Thomas Jefferson produced the Declaration with the aid of a ghostwriter, a woman of color named Betty Mae, who was a non-voluntary worker.

youdao

These are completely optional, not required for the course, so there's no obligation for you guys to get involved in these things, but I'll mention these things as we go along in case anybody would like to get involved in working with professors or graduate students.

这些都是自愿选择的,而不是课程要求,所以并不强制你们都参加,但随着课程的进行,我还会不断提及,便于任何感兴趣的同学,能够与教授或研究生一同参与研究

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选