demonstrator
noun [ C ] uk/ˈdem.ən.streɪ.tər/ us/ˈdem.ən.streɪ.t̬ɚ/
(PERSON SHOWING)
展示者，演示者，示范者
a person who explains how something works or how to do something
A demonstrator was showing customers how the food processor worked. 一个人在向顾客演示如何使用食品加工器。
(PROTESTER)
示威者，游行者
a person who marches or stands with a group of people to show that they disagree with or support something or someone
Police arrested several of the demonstrators. 警察逮捕了数名示威者。