Assertion: acrylic | /r/ObjectUse | used in submarine periscopes
Facets:
value: during ww2
type: TEMPORAL
value: historically
type: TEMPORAL
Source sentences:
text: Acrylic was historically used in submarine periscopes, windows for World War II jets, and as protective canopies and shields for turrets.
text: It was used for submarine periscopes and airplane turrets during WW2.