Until now, the comet had been unobserved for centuries.
Thankfully, my indiscretion went unobserved. Our team remained unobserved during the entire episode.
He hoped to return the package unobserved by anyone in the office. The sniper was unobserved as he moved stealthily through the forest.
You can use “unobserved” like this: “She left the room unobserved, hoping no one would notice her exit.” “The cat crept unobserved along the fence.” “He completed the task unobserved, avoiding any interruptions.” It basically means without being seen or noticed.
There isn't a perfect opposite, but depending on use, I suppose ignore or unobserved or conjecture or hypothetical or theoretical could work.
i do not know how to use embalming in a sentence. (there is the sentence)
Employ Sensors
employ sensors
employ sensors
So- you are asking when to use 'when' in a sentence. When you are asking how to use when in a question, you are already using when in a sentence, because a question actually is a sentence. I like to use when in a sentence whenever I like.
How do you use sedition in a sentence
use contingency in a sentence?
use adainty as sentence