demonstrator
n
1 person who teaches or explains by demonstrating (demonstrate 2) 示范助教
The demonstrators set up apparatus for the experiment. 示范助教安排好了实验装置.
2 person who demonstrates (demonstrate 3) 示威者; 游行者; 集会者
The noisy demonstrators were dispersed by the police. 喧嚷的示威者遭警察驱散.