Assertion: periscope | /r/ObjectUse | used for observation purposes
Facets:
value: during world war i
type: TEMPORAL
value: in the trenches
type: LOCATION
Source sentences:
text: The periscope is used in the submarines to see what is going on the water surface, It was used for observation purposes in the trenches during World War I, It is used in some gun turrets and it is used in armed vehicles.