Assertion: military grade nerve agent | /r/HasProperty | developed by the soviet union
Facets:
value: in 1980s
type: TEMPORAL
value: in the 1970s
type: TEMPORAL
Source sentences:
text: The military-grade nerve agent was developed by the Soviet Union in the 1970s and 1980s, and the Prime Minister has said it is "highly likely" Russia was responsible for the attack.