名詞 demonstrator:

1. a teacher or teacher's assistant who demonstrates the principles that are being taught
2. someone who demonstrates an article to a prospective buyer
   同義詞：sales demonstrator
3. someone who participates in a public display of group feeling
   同義詞：protester

1. The police estimated the number of demonstrators at about2000.
   警察估計(jì)示威游行的人數(shù)大約為2000人。
2. A surge of demonstrators broke through the fence.
   洶涌而來的示威者沖破了圍欄。

dem.on.stra.tor

n.（名詞）
One that demonstrates, such as a participant in a public display of opinion.
示威者：示威的人，例如一個(gè)表達(dá)意愿的公開集會(huì)的參加者
An article or product used in a demonstration.
示范品，樣品：用于展示的物品或產(chǎn)品