One who writes notes to explain a writing, book, etc.

(文字,书籍等之)注解者；注释者。

Person who discusses events on radio or television.

(收音机或电视上的)评论员；时事评论家。

A layman who leads a congregation in prayer at Mass or explains the rituals performed by the priest.

(弥撒的)非神职主祷人(带领参加弥撒的人群祈祷或解释教士所行的宗教仪式的俗人)。