观察员的英文：
observer

The old man was sent along as an observer.
那个老人被派作观察员。

You can't speak at this meeting, you are here as an oBserver.
你不能在会上发言，你只是个观察员。

Observers here say Yao can make a huge impact even in retirement.
观察员说姚明即使退役了也能起到非常大的作用。

An aircraft spotter,ie one who looks for and identifies different types of aircraft,esp in wartime
飞机观察员(寻找并辨认各类飞机的人,尤指战时)

We observed the barometer fall. [The barometer was observed to fall.]
我们看见晴雨表下降。

Observation is the best teacher.
观察是最好的老师。

They observed the behavior of their new pet.
他们观察他们新宠物的生活习性。

The professor is an acute observer.
那教授是位敏锐的观察家。

This suspect comes under observation.
这个可疑分子受到监视。