observing

The biologist spent hours observing the rare birds in their natural habitat.

生物学家花了数小时观察稀有鸟类在其自然栖息地中的行为。

用法提示：此处 observing 是动词的现在分词，表示‘仔细观察’的动作。

She kept observing the stranger from across the room, trying to figure out who he was.

她一直从房间另一边观察那个陌生人，试图弄清楚他是谁。

用法提示：此处 observing 是动词的现在分词，表示持续进行的‘注视’动作。

During the experiment, the assistant was carefully observing any changes in the chemical reaction.

实验期间，助手仔细地观察化学反应中的任何变化。

用法提示：此处 observing 是动词的过去进行时形式，强调‘观察’这一具体行为。