观察者

例句：

1. 1. The scientist is an observer of the latest developments in physics.
   这位科学家是物理学最新发展的观察者。
2. 2. The teacher asked the students to be observers during the experiment.
   老师要求学生们在实验中当观察者。
3. 3.As an observer, I was fascinated by the intricate details of the painting.
   作为观察者，我对这幅画的复杂细节感到着迷。