under close observation 严密观察
under medical observation 在医学观察中
be kept under observation 被持续观察
1. The patient is still under observation in the hospital.
病人仍在医院接受观察。
2. The suspect has been kept under observation by the police.
嫌疑人一直受到警方的监控。
3. The behavior of the animals is under observation for the study.
为了这项研究，这些动物的行为正处于观察中。
A: Why is the doctor staying so late?
A：医生为什么留到这么晚？
B: He is keeping the patient under observation.
B：他正在对病人进行观察。
1) 处于观察中
2) 受监控中
3) 接受监测
1. 处于观察中；受观察
e.g.
The suspect is being kept under observation.
嫌疑人正受到监控。
phrase
1. being watched or examined carefully to monitor a condition or behavior