Im which sentence is the word periscope used correctly excited about her finding, the scientist used a periscope to view the organisms in the water sample on the night of the full moon, we used the periscope to look at the sky sitting behind the tall stone walls, the soldier used a periscope to view the field surrounding the fort i held the periscope up to the light and was delighted with the many patterns i saw

the best sentence that suits for periscope is sitting behind the tall stone walls, the soldier used a periscope to view the field surrounding the forts.

the reason why I see the answer is that is because scientists don't use parascope to view organisms in the water sample, and we as people don't use Periscope to look at the sky when it's full moon, and when using periscope it don't delights with many patterns, so the answer is actually sitting behind the tall stone walls,the solider use the Periscope to view the field surrounding the forts.