1.[U,C]观察；观测；监视
2. 可数名词：（尤指据所见，所闻，所读而作的）评论 词形变化
- 形容词 observational
- 副词 observationally
- facts learned by observing
- the act of observing; taking a patient look
- the act of making and recording a measurement
- the act of noticing or paying attention
- a remark expressing careful consideration