We must observe silence in the library.
我们必须保持安静，因为现在在图书馆里。
Please observe the traffic lights while crossing the street.
过马路时请观察交通信号灯。
We need to observe the rules during the experiment.
实验过程中我们需要遵守规则。
You should observe the surroundings before making a move.
行动之前你应该先观察周围的环境。
Please observe from a distance to avoid disturbing the animals.
请保持距离观察，以免打扰动物。
She often goes afield to observe birds and insects.
她经常到野外去观察鸟类和昆虫。
Birders often carry binoculars to observe birds up close.
观鸟者通常会携带双筒望远镜来近距离观察鸟类。
Birdlife enthusiasts often observe birds in their natural habitats.
观鸟爱好者经常在自然栖息地观察鸟类。
We went to observe the process of milking cows.
我们去观察挤奶的过程。
They used a special astronomical instrument to observe the stars.
他们使用了一种特殊的天文仪器来观测星星。