A. Some people are so suicidal that they need to be under constant observation.

The movement of segments relative to one another is also under constant observation.

"We had the commander under constant observation and testing for three weeks."

The main one is under constant observation at the moment.

Since the day after their arrival the island had been kept under constant observation.

The President had held office for over three years, and was used to the constant observation.

Day and night the light remained on as guards kept him under constant observation.

So their suspicion was correct: they were under constant observation.

Their purpose clearly was to make everyone feel under constant observation.

He had been under constant observation for two months before his death.