She is there to instruct people in the safe use of the gym equipment.

### 解释 instruct 是动词，由前缀 in-（表示"进入、向内"）和词根 struct（来自拉丁语 struere，意为"建造、组织"）组成，字面意思是"将知识或技能构建进某人"，引申为"教导、指导"的意思。