They finely crush this "crumb" mixture so it is smooth.

VOA: special.2010.02.17

They like to hear the music of a smooth voice and so on.

婴儿们喜欢听到拥有平缓声音的音乐等等

耶鲁公开课 - 心理学导论课程节选

So if there's any systematic bias going on in the way these things get graded it'll smooth itself out across the teaching fellows, so we'll have a fair grading system and things.

所以,如果在评分过程中,有任何系统性误差,都会由助教们尽量纠正过来,这样就有了公平的评分系统

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选